CVE-2011-4954 in Cobbler
Summary
by MITRE
cobbler has local privilege escalation via the use of insecure location for PYTHON_EGG_CACHE
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Analysis
by VulDB Data Team • 02/23/2024
The vulnerability identified as CVE-2011-4954 affects the cobbler system management tool, specifically targeting a local privilege escalation flaw through insecure handling of the PYTHON_EGG_CACHE environment variable. This issue arises from the improper configuration of temporary file storage locations that can be manipulated by local attackers to gain elevated privileges on the system. The vulnerability stems from the application's failure to properly validate or sanitize the PYTHON_EGG_CACHE variable, which is commonly used by python applications to store temporary egg files during package installation and execution processes.
The technical implementation of this vulnerability exploits the predictable and writable nature of the PYTHON_EGG_CACHE location, allowing attackers to place malicious python egg files that will be executed with elevated privileges when the cobbler service runs. This creates a classic privilege escalation vector where a local user can manipulate the execution environment to inject code that will run with the privileges of the cobbler service account. The flaw specifically relates to CWE-276, which addresses incorrect permissions for ancillary files and access control, and CWE-73, which covers external control of data flow, as the environment variable can be manipulated by unprivileged users to influence program behavior. The vulnerability can be leveraged through the ATT&CK technique T1068, which involves exploiting legitimate credentials and privileges to gain elevated access.
The operational impact of this vulnerability is significant as it allows local attackers to escalate their privileges to the level of the cobbler service, which typically runs with administrative or root-like privileges depending on the system configuration. This can lead to complete system compromise, as the attacker can then access sensitive data, modify system configurations, install backdoors, or perform other malicious activities that require elevated privileges. The vulnerability is particularly dangerous in environments where cobbler is used for automated system provisioning and management, as these systems often require high privileges to function correctly. Attackers can exploit this vulnerability without requiring remote network access, making it a serious concern for systems where local security is not properly enforced.
Mitigation strategies for CVE-2011-4954 should focus on implementing proper environment variable validation and ensuring that the PYTHON_EGG_CACHE location is properly secured with appropriate permissions. System administrators should configure the cobbler service to use secure temporary directories with restricted write permissions and ensure that the PYTHON_EGG_CACHE environment variable is either unset or points to a secure location that cannot be manipulated by unprivileged users. Additionally, the system should be configured to run cobbler with the principle of least privilege, ensuring that it only has the necessary permissions to perform its intended functions. Regular security audits should verify that no insecure temporary file locations are being used by the application, and that proper access controls are in place to prevent local privilege escalation attacks. The fix should also include implementing proper input validation and sanitization for environment variables, following security best practices outlined in industry standards and security frameworks.