CVE-2012-0950 in Linux
Summary
by MITRE
The Apport hook (DistUpgradeApport.py) in Update Manager, as used by Ubuntu 12.04 LTS, 11.10, and 11.04, uploads the /var/log/dist-upgrade directory when reporting bugs to Launchpad, which allows remote attackers to read repository credentials by viewing a public bug report. NOTE: this vulnerability exists because of an incomplete fix for CVE-2012-0949.
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Analysis
by VulDB Data Team • 12/04/2021
The vulnerability described in CVE-2012-0950 represents a critical information disclosure flaw within Ubuntu's Update Manager system, specifically affecting versions 11.04, 11.10, and 12.04 LTS. This security issue stems from the improper handling of sensitive data during the bug reporting process, where the Apport hook mechanism fails to adequately sanitize the contents of the /var/log/dist-upgrade directory before uploading to Launchpad. The flaw creates a significant exposure risk by allowing remote attackers to access repository credentials through public bug reports, fundamentally undermining the security posture of affected systems.
The technical implementation of this vulnerability occurs through the DistUpgradeApport.py hook within the Apport crash reporting framework, which is integrated into the Update Manager's bug reporting functionality. When users submit bug reports related to system upgrades, the system automatically includes log files from the /var/log/dist-upgrade directory without proper filtering or sanitization of sensitive information. This directory contains detailed upgrade logs that may include authentication tokens, repository URLs with embedded credentials, and other sensitive configuration data. The vulnerability manifests as an incomplete remediation of CVE-2012-0949, indicating that previous efforts to address similar issues were insufficient, leaving persistent exposure pathways for attackers to exploit.
The operational impact of this vulnerability extends beyond simple credential theft, as it enables attackers to gain unauthorized access to software repositories and potentially compromise entire system update processes. Attackers can systematically monitor public Launchpad bug reports to identify vulnerable systems and extract repository credentials that may grant them access to additional software packages and updates. This creates a persistent threat vector where attackers can maintain access to software repositories, potentially enabling them to introduce malicious packages or manipulate the software supply chain. The vulnerability particularly affects enterprise environments where automated system updates and repository management are critical components of security infrastructure.
Mitigation strategies for this vulnerability require immediate system hardening measures including the implementation of proper log sanitization procedures and the modification of Apport hook configurations to exclude sensitive directories from automatic uploads. System administrators should disable or modify the DistUpgradeApport.py hook functionality, implement custom log filtering rules, and establish monitoring procedures to detect unauthorized access to bug reports containing sensitive information. Organizations must also consider updating to patched versions of Ubuntu that address this vulnerability, while implementing network segmentation and access controls to limit exposure of sensitive upgrade logs. The flaw aligns with CWE-200 (Information Exposure) and represents a significant weakness in the principle of least privilege, as demonstrated through ATT&CK techniques related to credential access and information gathering.
This vulnerability highlights the importance of comprehensive security testing for automated reporting systems and demonstrates how seemingly minor configuration issues can create substantial security risks. The incomplete fix for CVE-2012-0949 indicates a pattern of inadequate security review processes that allowed similar vulnerabilities to persist in the system's core functionality. Organizations should implement regular security assessments of their automated systems and maintain strict controls over log file contents to prevent similar exposure scenarios. The remediation process requires careful consideration of the balance between system diagnostics and security, ensuring that debugging information does not compromise system integrity while maintaining operational visibility for legitimate troubleshooting purposes.