CVE-2021-29429 : Exploit Details and Defense Strategies

In Gradle before version 7.0, files created with open permissions in the system temporary directory can allow an attacker to access information downloaded by Gradle. Some builds could be vulnerable to a local information disclosure. Remote files accessed through TextResourceFactory are downloaded into the system temporary directory first. Sensitive information contained in these files can be exposed to other local users on the same system. If you do not use the

TextResourceFactory

API, you are not vulnerable. As of Gradle 7.0, uses of the system temporary directory have been moved to the Gradle User Home directory. By default, this directory is restricted to the user running the build. As a workaround, set a more restrictive umask that removes read access to other users. When files are created in the system temporary directory, they will not be accessible to other users. If you are unable to change your system's umask, you can move the Java temporary directory by setting the System Property

java.io.tmpdir

. The new path needs to limit permissions to the build user only.

Understanding CVE-2021-29429

This CVE highlights the risk of information disclosure through improper permissions in the temporary directory utilized by Gradle.

What is CVE-2021-29429?

CVE-2021-29429 details an issue in Gradle versions prior to 7.0, where files created with open permissions in the system temporary directory are susceptible to exploitation by attackers.

The Impact of CVE-2021-29429

The vulnerability can lead to local information disclosure, exposing sensitive data to unauthorized local users sharing the system.

Technical Details of CVE-2021-29429

This section covers specifics regarding the vulnerability.

Vulnerability Description

The vulnerability arises from files created with open permissions in the system temporary directory accessible to attackers, potentially leading to the exposure of sensitive information.

Affected Systems and Versions

Gradle versions prior to 7.0 are affected by this vulnerability, emphasizing the importance of updating to the latest secure version.

Exploitation Mechanism

Attackers can exploit this vulnerability through the system temporary directory used by Gradle, gaining unauthorized access to downloaded information.

Mitigation and Prevention

Learn how to mitigate the risks posed by CVE-2021-29429 to enhance your system's security.

Immediate Steps to Take

Take immediate precautions, such as setting restrictive umask and changing Java temporary directory permissions.

Long-Term Security Practices

Implement long-term security measures like regularly updating Gradle to ensure protection against known vulnerabilities.

Patching and Updates

Stay informed about security advisories and promptly apply patches and updates to safeguard your system.