CVE-2012-0962 in Aptdaemon
Summary
by MITRE
Aptdaemon 0.43 in Ubuntu 11.10 and 12.04 LTS uses short IDs when importing PPA GPG keys from a keyserver, which allows remote attackers to install arbitrary package repository GPG keys via a man-in-the-middle (MITM) attack.
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Analysis
by VulDB Data Team • 12/21/2021
The vulnerability described in CVE-2012-0962 represents a critical security flaw in the aptdaemon package management system used by Ubuntu 11.10 and 12.04 LTS distributions. This issue stems from the improper handling of GPG key imports during package repository management operations, creating a significant attack surface that adversaries can exploit to compromise system integrity. The vulnerability specifically affects the process by which PPA (Personal Package Archive) GPG keys are retrieved from key servers, where the system employs short key identifiers instead of full fingerprints, making the authentication process susceptible to cryptographic attacks.
The technical flaw manifests in the cryptographic weakness of using short key IDs for GPG key verification during the aptdaemon package installation process. When importing GPG keys from key servers, the system relies on 32-bit key identifiers rather than the full 160-bit key fingerprints that are typically required for secure key identification. This practice creates a collision vulnerability where an attacker can potentially generate a fake GPG key that matches the short ID of a legitimate repository key, thereby enabling successful man-in-the-middle attacks. The weakness is classified under CWE-327, which addresses the use of weak cryptographic algorithms and key management practices, particularly in the context of key identification and verification processes.
The operational impact of this vulnerability is severe and far-reaching, as it allows remote attackers to execute arbitrary code on affected systems through legitimate package management operations. An attacker positioned in a man-in-the-middle position can intercept network traffic between the vulnerable system and the keyserver, substituting legitimate repository keys with malicious ones that share the same short key ID. This enables the attacker to distribute and install packages that appear to come from trusted sources, effectively bypassing the security mechanisms designed to prevent unauthorized package installation. The attack can lead to complete system compromise, data exfiltration, and persistent backdoor access, making it particularly dangerous in enterprise environments where package management is a routine administrative task.
Mitigation strategies for this vulnerability require immediate implementation of several security measures to protect affected systems. Organizations should upgrade to patched versions of aptdaemon that implement proper full-key fingerprint verification instead of short ID matching, which aligns with the ATT&CK technique T1553.003 for subtechnique 3 related to credential access through key management vulnerabilities. System administrators should also implement additional network security controls such as DNSSEC validation, certificate pinning for keyserver communications, and network monitoring to detect suspicious keyserver traffic patterns. The recommended approach includes disabling automatic PPA key imports and manually verifying all repository keys through secure channels, while also implementing network segmentation to limit the attack surface of package management operations. Additionally, organizations should consider implementing automated security scanning tools that can detect and alert on potential key collision attempts, ensuring that the security posture remains robust against this specific class of cryptographic attack.