CVE-2007-1507 in OpenAFS
Summary
by MITRE
The default configuration in OpenAFS 1.4.x before 1.4.4 and 1.5.x before 1.5.17 supports setuid programs within the local cell, which might allow attackers to gain privileges by spoofing a response to an AFS cache manager FetchStatus request, and setting setuid and root ownership for files in the cache.
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Analysis
by VulDB Data Team • 07/17/2019
The vulnerability described in CVE-2007-1507 represents a critical privilege escalation flaw within the OpenAFS distributed file system implementation. This issue affects OpenAFS versions 1.4.x prior to 1.4.4 and 1.5.x prior to 1.5.17, where the default configuration inadvertently permits setuid programs to execute within the local cell environment. The flaw stems from insufficient validation mechanisms within the AFS cache manager's FetchStatus request processing, creating a pathway for malicious actors to manipulate file permissions and ownership. The vulnerability operates by exploiting the trust relationship between the cache manager and the AFS cell, allowing attackers to craft spoofed responses that manipulate how the system handles file ownership and permissions.
The technical implementation of this vulnerability involves the manipulation of AFS cache manager operations during FetchStatus requests, where the system's default configuration fails to properly validate the authenticity of responses received from the AFS cell. When setuid programs are executed within the local cell, the cache manager's response handling mechanism can be tricked into setting incorrect file ownership and permissions, specifically allowing the assignment of root ownership and setuid bits to files within the cache. This creates a persistent privilege escalation vector that can be exploited by attackers with network access to the AFS cell. The vulnerability is particularly dangerous because it leverages the legitimate trust relationships within the AFS architecture to execute malicious operations that would otherwise be prohibited.
From an operational impact perspective, this vulnerability enables attackers to gain root-level privileges on systems running vulnerable OpenAFS versions, potentially leading to complete system compromise and unauthorized access to sensitive data. The exploitation requires network access to the AFS cell and knowledge of the cache manager's operation, but does not require authentication to the AFS cell itself. Once successfully exploited, attackers can maintain persistent access through the setuid programs they have installed, creating a backdoor that can be used for further reconnaissance, lateral movement, or data exfiltration. The vulnerability affects organizations that rely on OpenAFS for distributed file services and may have been exploited in targeted attacks against high-value systems.
The mitigation strategy for this vulnerability involves upgrading to OpenAFS versions 1.4.4 or 1.5.17 and later, which contain the necessary patches to address the improper validation of cache manager responses. System administrators should also review the default configuration settings to ensure that setuid programs are not unnecessarily permitted within the local cell, and implement proper network segmentation to limit access to AFS services. The vulnerability aligns with CWE-276, which describes improper file permissions, and can be mapped to ATT&CK technique T1068, which covers privilege escalation through local exploits. Organizations should also consider implementing monitoring for unusual setuid program execution and file permission changes within their AFS environments to detect potential exploitation attempts.