CVE-2023-26054 : Exploit Details and Defense Strategies

This CVE-2023-26054 involves credentials inlined to Git URLs that could end up in provenance attestation in BuildKit. It was published on March 6, 2023.

Understanding CVE-2023-26054

This vulnerability pertains to BuildKit, a toolkit for converting source code to build artifacts efficiently and expressively. In affected versions, credentials included in Git URLs could potentially be exposed in provenance attestations, leading to sensitive information exposure.

What is CVE-2023-26054?

When a user submits a build request with a Git URL containing credentials, and a provenance attestation is generated, these credentials become visible within the provenance attestation. This exposure occurs under specific conditions, such as invoking builds directly from URLs with credentials or passing VCS hint parameters on builds originating from local sources.

The Impact of CVE-2023-26054

The vulnerability exposes sensitive information to unauthorized actors, particularly in scenarios where build requests contain Git URLs with credentials. This exposure could lead to unauthorized access to the provenance attestation, compromising the security of the build environment.

Technical Details of CVE-2023-26054

This section dives into the vulnerability description, affected systems and versions, as well as the exploitation mechanism.

Vulnerability Description

In versions of BuildKit between >= 0.10.0 and < 0.11.4, credentials within Git URLs used in build requests may be visible in provenance attestations. This exposure occurs when builds are initiated with specific parameters hinting at VCS information or when Git URLs with credentials are directly employed.

Affected Systems and Versions

The vulnerability impacts versions of BuildKit ranging from >= 0.10.0 to < 0.11.4. Versions before v0.11.0 are not vulnerable, as the issue lies in the handling of provenance attestations that were introduced in this version.

Exploitation Mechanism

The vulnerability can be exploited by submitting build requests with Git URLs containing credentials or by utilizing VCS hint parameters during builds from local sources. Under these conditions, the credentials become accessible in the generated provenance attestations.

Mitigation and Prevention

To address CVE-2023-26054, users should take immediate steps to secure their BuildKit environment, implement long-term security practices, and apply the necessary patches and updates.

Immediate Steps to Take

Upgrade to version v0.11.4 or later, where the vulnerability has been fixed.
If upgrading is not feasible, disable VCS info hints by setting

BUILDX_GIT_INFO=0

to prevent credential exposure.
Manually pass VCS hint values with

--opt

when using

buildctl

to avoid hints based on the

.git

directory.

Long-Term Security Practices

Regularly monitor for security advisories and updates related to BuildKit.
Implement secure coding practices and avoid including sensitive information in build requests.
Educate users on the importance of secure credential management and data protection.

Patching and Updates

Stay informed about security patches and updates released by BuildKit. Timely application of these patches is crucial to address vulnerabilities and enhance the security of your BuildKit environment.