Vulnerabilities > CVE-2023-26054 - Information Exposure vulnerability in Mobyproject Buildkit
Summary
BuildKit is a toolkit for converting source code to build artifacts in an efficient, expressive and repeatable manner. In affected versions when the user sends a build request that contains a Git URL that contains credentials and the build creates a provenance attestation describing that build, these credentials could be visible from the provenance attestation. Git URL can be passed in two ways: 1) Invoking build directly from a URL with credentials. 2) If the client sends additional version control system (VCS) info hint parameters on builds from a local source. Usually, that would mean reading the origin URL from `.git/config` file. When a build is performed under specific conditions where credentials were passed to BuildKit they may be visible to everyone who has access to provenance attestation. Provenance attestations and VCS info hints were added in version v0.11.0. Previous versions are not vulnerable. In v0.10, when building directly from Git URL, the same URL could be visible in `BuildInfo` structure that is a predecessor of Provenance attestations. Previous versions are not vulnerable. This bug has been fixed in v0.11.4. Users are advised to upgrade. Users unable to upgrade may disable VCS info hints by setting `BUILDX_GIT_INFO=0`. `buildctl` does not set VCS hints based on `.git` directory, and values would need to be passed manually with `--opt`.
Vulnerable Configurations
Common Weakness Enumeration (CWE)
Common Attack Pattern Enumeration and Classification (CAPEC)
- Subverting Environment Variable Values The attacker directly or indirectly modifies environment variables used by or controlling the target software. The attacker's goal is to cause the target software to deviate from its expected operation in a manner that benefits the attacker.
- Footprinting An attacker engages in probing and exploration activity to identify constituents and properties of the target. Footprinting is a general term to describe a variety of information gathering techniques, often used by attackers in preparation for some attack. It consists of using tools to learn as much as possible about the composition, configuration, and security mechanisms of the targeted application, system or network. Information that might be collected during a footprinting effort could include open ports, applications and their versions, network topology, and similar information. While footprinting is not intended to be damaging (although certain activities, such as network scans, can sometimes cause disruptions to vulnerable applications inadvertently) it may often pave the way for more damaging attacks.
- Exploiting Trust in Client (aka Make the Client Invisible) An attack of this type exploits a programs' vulnerabilities in client/server communication channel authentication and data integrity. It leverages the implicit trust a server places in the client, or more importantly, that which the server believes is the client. An attacker executes this type of attack by placing themselves in the communication channel between client and server such that communication directly to the server is possible where the server believes it is communicating only with a valid client. There are numerous variations of this type of attack.
- Browser Fingerprinting An attacker carefully crafts small snippets of Java Script to efficiently detect the type of browser the potential victim is using. Many web-based attacks need prior knowledge of the web browser including the version of browser to ensure successful exploitation of a vulnerability. Having this knowledge allows an attacker to target the victim with attacks that specifically exploit known or zero day weaknesses in the type and version of the browser used by the victim. Automating this process via Java Script as a part of the same delivery system used to exploit the browser is considered more efficient as the attacker can supply a browser fingerprinting method and integrate it with exploit code, all contained in Java Script and in response to the same web page request by the browser.
- Session Credential Falsification through Prediction This attack targets predictable session ID in order to gain privileges. The attacker can predict the session ID used during a transaction to perform spoofing and session hijacking.
References
- https://github.com/moby/buildkit/commit/75123c696506bdbca1ed69906479e200f1b62604
- https://github.com/moby/buildkit/security/advisories/GHSA-gc89-7gcr-jxqc
- https://lists.fedoraproject.org/archives/list/[email protected]/message/ZTE4ITXXPIWZEQ4HYQCB6N6GZIMWXDAI/
- https://lists.fedoraproject.org/archives/list/[email protected]/message/LYZOKMMVX4SIEHPJW3SJUQGMO5YZCPHC/
- https://lists.fedoraproject.org/archives/list/[email protected]/message/XNF4OLYZRQE75EB5TW5N42FSXHBXGWFE/