CVE-2012-0420 in Zypper
Summary
by MITRE
zypp-refresh-wrapper in SUSE Zypper before 1.3.20 and 1.6.x before 1.6.166 allows local users to create files in arbitrary directories, or possibly have unspecified other impact, via a pathname in the ZYPP_LOCKFILE_ROOT environment variable.
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Analysis
by VulDB Data Team • 01/04/2025
The vulnerability identified as CVE-2012-0420 affects the zypp-refresh-wrapper component within SUSE Zypper package management system. This issue exists in versions prior to 1.3.20 and 1.6.x prior to 1.6.166, representing a critical security flaw that enables local attackers to manipulate file creation permissions within the system. The vulnerability stems from improper handling of the ZYPP_LOCKFILE_ROOT environment variable, which is designed to control lock file locations during package management operations.
The technical flaw manifests through the insecure processing of the ZYPP_LOCKFILE_ROOT environment variable, which allows attackers to specify arbitrary directory paths for file creation operations. When this environment variable is manipulated by a local user, the zypp-refresh-wrapper component fails to properly validate or sanitize the specified pathname, enabling potential privilege escalation or unauthorized file system modifications. This vulnerability operates under the principle of insecure direct object reference, where user-controllable input directly influences system resource access without proper validation mechanisms.
The operational impact of this vulnerability extends beyond simple file creation capabilities, potentially allowing attackers to establish persistent access points or manipulate critical system files. Local users with minimal privileges could leverage this flaw to create files in directories they normally wouldn't have write permissions, effectively bypassing standard access controls. The unspecified other impacts suggest potential for more severe consequences including privilege escalation, denial of service, or system compromise depending on the specific execution context. This vulnerability directly relates to CWE-22, which addresses improper limitation of a pathname to a restricted directory, commonly known as path traversal attacks.
From an adversarial perspective, this vulnerability aligns with ATT&CK technique T1068, which involves exploiting local system privileges to gain elevated access. Attackers could potentially use this flaw to modify package management components, inject malicious code, or establish backdoors within the system. The attack surface is particularly concerning in multi-user environments where local privilege escalation opportunities could lead to broader system compromise. Organizations should consider this vulnerability as part of a broader attack chain that could enable more sophisticated compromises when combined with other local privilege escalation techniques.
The recommended mitigations include immediate patching of affected Zypper versions to 1.3.20 or 1.6.166 and higher, implementing proper environment variable validation within package management systems, and conducting comprehensive system audits to identify any potential exploitation attempts. System administrators should also review and restrict environment variable usage in package management contexts, particularly those that influence file system operations. Additionally, monitoring for unusual file creation patterns in system directories and implementing proper access controls can help detect and prevent exploitation attempts. The vulnerability highlights the importance of secure coding practices in system administration tools and the necessity of validating all user-controllable inputs before processing them within privileged contexts.