CVE-2011-1829 in APT
Summary
by MITRE
APT before 0.8.15.2 does not properly validate inline GPG signatures, which allows man-in-the-middle attackers to install modified packages via vectors involving lack of an initial clearsigned message.
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Analysis
by VulDB Data Team • 11/15/2021
The vulnerability identified as CVE-2011-1829 affects APT package management systems prior to version 0.8.15.2, representing a critical flaw in the handling of GPG signature validation. This weakness stems from insufficient validation mechanisms for inline GPG signatures, creating a pathway for malicious actors to compromise system integrity through man-in-the-middle attacks. The vulnerability specifically targets the absence of proper signature verification during package installation processes, allowing attackers to inject modified packages into the update pipeline. The flaw exploits the lack of initial clearsigned message validation, which is essential for establishing trust in package authenticity.
The technical implementation of this vulnerability resides in the APT package manager's cryptographic validation routines, where inline GPG signatures are processed without adequate verification of their integrity. This allows attackers to manipulate package contents while maintaining the appearance of legitimate software updates. The flaw operates at the core of package management security protocols, specifically targeting the trust model that APT uses to validate software authenticity. When APT processes packages with inline signatures, it fails to properly cross-reference the signature against the package content, enabling attackers to forge signatures that appear valid to the system.
Operationally, this vulnerability presents significant risks to system security and integrity, as it allows attackers to execute arbitrary code through compromised package installations. The man-in-the-middle attack vector means that adversaries can intercept package downloads and modify them before installation, potentially introducing backdoors, malware, or other malicious components. The impact extends beyond individual system compromise to potential network-wide infiltration, especially in environments where APT is used for automated updates. Organizations relying on APT for package management face substantial risk of unauthorized system access and data breaches when this vulnerability remains unpatched.
The vulnerability aligns with CWE-347, which addresses improper validation of cryptographic signatures, and relates to ATT&CK technique T1547.001 for establishing persistence through package management. Mitigation strategies should prioritize immediate patching to APT version 0.8.15.2 or later, which implements proper inline GPG signature validation. System administrators should also implement additional security controls such as verifying package integrity through multiple channels, monitoring package installation logs for suspicious activity, and employing network segmentation to limit attack surface. Organizations should consider implementing automated patch management systems to ensure timely vulnerability remediation and establish baseline security configurations that enforce strict signature validation requirements. Regular security audits of package management systems and network traffic monitoring can help detect potential exploitation attempts and maintain overall system security posture.