CVE-2005-1111 in cpio
Summary
by MITRE
race condition in cpio 2.6 and earlier allows local users to modify permissions of arbitrary files via a hard link attack on a file while it is being decompressed whose permissions are changed by cpio after the decompression is complete.
If you want to get the best quality for vulnerability data then you always have to consider VulDB.
Analysis
by VulDB Data Team • 06/02/2019
The vulnerability identified as CVE-2005-1111 represents a significant race condition flaw within the cpio archival utility version 2.6 and earlier. This issue arises from the improper handling of file permissions during the decompression process, creating a window of opportunity for malicious local users to exploit the system. The flaw specifically manifests when cpio processes files that have their permissions modified after the decompression operation completes, allowing attackers to manipulate file access controls through carefully crafted hard link attacks. This vulnerability falls under the category of time-of-check to time-of-use race conditions, where the system's state changes between the point of verification and the point of action, creating exploitable conditions.
The technical implementation of this vulnerability stems from cpio's failure to properly synchronize file operations during decompression, particularly when dealing with files that require permission modifications post-extraction. When cpio encounters a file that needs permission changes, it performs the decompression first and then applies the permission modifications afterward, creating a temporal gap where the system state is inconsistent. Attackers can exploit this gap by creating hard links to target files and manipulating the file system during this window, potentially allowing them to change permissions of files they would not normally have access to modify. This attack vector directly relates to CWE-367, which describes time-of-check to time-of-use race conditions, and demonstrates how improper synchronization can lead to privilege escalation.
The operational impact of this vulnerability extends beyond simple permission manipulation, as it can enable local users to gain unauthorized access to sensitive system resources. An attacker who successfully exploits this race condition can effectively bypass normal file system permission controls, potentially allowing them to modify critical system files, escalate privileges, or establish persistent access to the compromised system. The vulnerability is particularly concerning in multi-user environments where local users might not have elevated privileges but could leverage this flaw to compromise system integrity. This weakness can be exploited in various scenarios including system maintenance, software installation, or routine file operations where cpio is used, making it a persistent threat that can be triggered during normal system operation.
Mitigation strategies for CVE-2005-1111 require immediate system updates to cpio versions that address the race condition through proper synchronization mechanisms. Organizations should prioritize patching affected systems and implementing monitoring to detect potential exploitation attempts. Additionally, system administrators should review and restrict the use of cpio in environments where untrusted users might have access to system resources. The implementation of proper file system permissions and access controls can help limit the impact of such vulnerabilities, while regular security audits should verify that no other similar race conditions exist in the system's toolset. This vulnerability demonstrates the importance of proper synchronization in system utilities and highlights the need for comprehensive security testing of core system components that handle file operations and permission modifications. The ATT&CK framework categorizes this as a privilege escalation technique, specifically leveraging race conditions in system utilities to gain unauthorized access to system resources.