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Overview

com.nimbusds:nimbus-jose-jwt is a library for JSON Web Tokens (JWT)

Affected versions of this package are vulnerable to Uncontrolled Recursion due to the improper handling JWT claim sets containing deeply nested JSON objects. An attacker can cause application downtime or resource exhaustion by submitting a specially crafted JWT with excessive nesting.

Note:

This issue only affects nimbus-jose-jwt, not Gson because the Connect2id product could have checked the JSON object nesting depth, regardless of what limits (if any) were imposed by Gson.

PoC

import com.nimbusds.jwt.JWTClaimsSet;
import java.text.ParseException;
import java.util.HashMap;
import java.util.Map;

public class Test {
    // This builds a claimset with a deeply nested map, which could theoretically be supplied by a client.
    // If the JWT is serialized into JSON (for example, in logging or debugging), it can cause a StackOverflowError.
    public static void main(String[] args) throws ParseException {        
        Map<String, Object> nestedMap = new HashMap<>();
        Map<String, Object> currentLevel = nestedMap;

        for (int i = 0; i < 5000; i++) {
            Map<String, Object> nextLevel = new HashMap<>();
            currentLevel.put("", nextLevel);
            currentLevel = nextLevel;
        }

        JWTClaimsSet claimSet = JWTClaimsSet.parse(nestedMap);

        // This will cause a StackOverflowError due to excessive recursion in GSON's serialization
        claimSet.toString();
    }
}

Remediation

Upgrade com.nimbusds:nimbus-jose-jwt to version 9.37.4, 10.0.2 or higher.

References

• Bitbucket Commit
• Bitbucket Issue
• Bitbucket Issue
• GitHub Commit

Overview

com.nimbusds:nimbus-jose-jwt is a library for JSON Web Tokens (JWT)

Affected versions of this package are vulnerable to Improper Check for Unusual or Exceptional Conditions. Can throw various uncaught exceptions while parsing a JWT, which could result in an application crash (potential information disclosure) or a potential authentication bypass.

Remediation

Upgrade com.nimbusds:nimbus-jose-jwt to version 7.8.1 or higher.

References

• Apache Security Advisory
• Blog Post
• PoC
• Security Changelog

Overview

net.minidev:json-smart is a Java JSON parser.

Affected versions of this package are vulnerable to Denial of Service (DoS). An exception is thrown from a function, but it is not caught, as demonstrated by NumberFormatException. When it is not caught, it may cause programs using the library to crash or expose sensitive information.

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 net.minidev:json-smart to version 1.3.2, 2.3.1, 2.4.1 or higher.

References

• GitHub Issue - Json Smart V1
• GitHub Issue - Json Smart V2

Overview

net.minidev:json-smart is a Java JSON parser.

Affected versions of this package are vulnerable to Denial of Service (DoS) via the indexOf function of JSONParserByteArray which causes a denial of service (DOS) via a crafted web request.

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 net.minidev:json-smart to version 1.3.3, 2.4.5 or higher.

References

• GitHub Issue
• GitHub Issue
• GitHub PR
• GitHub PR