CVE-2005-2693 in cvs
Summary
by MITRE
cvsbug in CVS 1.12.12 and earlier creates temporary files insecurely, which allows local users to overwrite arbitrary files and execute arbitrary code via a symlink attack.
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Analysis
by VulDB Data Team • 06/29/2025
The vulnerability identified as CVE-2005-2693 resides within the Concurrent Versions System (CVS) version control software, specifically affecting versions 1.12.12 and earlier. This flaw represents a critical security issue that stems from insecure temporary file creation practices within the cvsbug utility, which is part of the broader CVS suite designed for software configuration management. The vulnerability enables local attackers to exploit the insecure file handling mechanisms to overwrite arbitrary files and subsequently execute malicious code, making it particularly dangerous in environments where users may have limited privileges but can still interact with the system.
The technical root cause of this vulnerability lies in the improper handling of temporary files during the execution of the cvsbug utility. When the utility creates temporary files, it does not adequately verify the existence or ownership of these files before writing to them, creating a window of opportunity for attackers to establish symbolic links with predictable names that point to sensitive system files. This insecure temporary file creation pattern falls under the category of insecure temporary file handling as classified by CWE-377, which specifically addresses the creation of temporary files with insecure permissions or predictable names. The flaw allows an attacker to manipulate the temporary file creation process through a symlink attack, where the attacker creates symbolic links in the temporary directory that will be accessed by the vulnerable cvsbug utility, effectively redirecting file operations to arbitrary locations on the filesystem.
The operational impact of CVE-2005-2693 extends beyond simple privilege escalation, as it provides attackers with the capability to execute arbitrary code with the privileges of the user running the cvsbug utility. This vulnerability is particularly concerning in multi-user environments where users may not have direct administrative access but can still influence the execution of CVS operations. The attack vector requires local access and the ability to create symbolic links in directories where the vulnerable utility operates, which is often feasible in shared development environments where users have write permissions to temporary directories. The vulnerability can be exploited to overwrite critical system files, configuration files, or even binaries that are executed by the system, potentially leading to complete system compromise. This type of attack aligns with the ATT&CK framework's privilege escalation techniques, specifically targeting local privilege escalation through insecure file handling and symbolic link manipulation.
The remediation for this vulnerability involves upgrading to CVS version 1.12.13 or later, which contains patches addressing the insecure temporary file creation behavior. System administrators should also implement proper file system permissions and access controls to limit the ability of users to create symbolic links in directories where vulnerable utilities operate. Additional mitigations include monitoring for suspicious symbolic link creation patterns in temporary directories and implementing privilege separation for CVS operations. Organizations should also consider implementing mandatory access controls or security modules like SELinux to further restrict the impact of such vulnerabilities. The vulnerability demonstrates the importance of secure coding practices in file handling operations and the need for regular security assessments of system utilities, particularly those that may be executed with elevated privileges or in shared environments. This issue highlights the broader category of race condition vulnerabilities and insecure temporary file handling that can be exploited to gain unauthorized access to system resources and execute malicious code through manipulation of file system operations.