CVE-2022-4122 in podman
Summary
by MITRE • 12/08/2022
A vulnerability was found in buildah. Incorrect following of symlinks while reading .containerignore and .dockerignore results in information disclosure.
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Analysis
by VulDB Data Team • 04/23/2025
The vulnerability identified as CVE-2022-4122 resides within the buildah container image building tool, specifically concerning how it processes symbolic links during the parsing of .containerignore and .dockerignore configuration files. This flaw represents a critical security oversight that allows unauthorized information disclosure through improper symlink handling mechanisms. The issue stems from the tool's failure to properly validate or restrict symbolic link traversal when processing ignore files that control which files and directories are excluded from container image builds.
The technical implementation of this vulnerability involves buildah's path resolution logic not adequately sanitizing symbolic link references within the ignore file processing pipeline. When buildah encounters symbolic links in .containerignore or .dockerignore files, it fails to properly resolve these links or validate their targets against the intended exclusion scope. This misconfiguration enables an attacker to craft malicious symlink structures that can bypass the intended exclusion behavior, potentially exposing sensitive files or directories that should have been excluded from the container image construction process.
From an operational security perspective, this vulnerability presents significant risks to containerized environments where buildah is utilized for image creation. An attacker with access to the build environment or the ability to influence the build process can exploit this weakness to disclose files that contain sensitive information such as credentials, configuration data, or proprietary code that should remain excluded from container images. The impact extends beyond simple information disclosure to potentially enable further attacks through exposure of system artifacts or secrets that could be leveraged for privilege escalation or lateral movement within containerized infrastructures.
The vulnerability aligns with CWE-59, which specifically addresses improper following of symbolic links, and demonstrates characteristics consistent with path traversal attacks that can be classified under ATT&CK technique T1059.007 for command and scripting interpreter. Organizations utilizing buildah for container image creation should consider this vulnerability as a potential entry point for adversaries seeking to extract sensitive information from build environments or container images. The flaw particularly affects environments where buildah processes user-provided ignore files without proper validation of symbolic link integrity.
Mitigation strategies should focus on implementing proper symlink validation mechanisms within buildah's file processing pipeline, ensuring that symbolic links are either resolved safely or explicitly rejected during ignore file parsing. Organizations should also consider implementing build environment restrictions that prevent untrusted users from injecting malicious symlink structures into the build process. Updates to buildah versions that address this specific symlink handling behavior should be prioritized, along with comprehensive review of existing container build processes to identify potential exploitation vectors. Additionally, implementing proper access controls and build environment isolation can help reduce the attack surface and limit the potential impact of this vulnerability.