CVE-2002-1512 in BRU
Summary
by MITRE
xbru in BRU Workstation 17.0 allows local users to overwrite arbitrary files and gain root privileges via a symlink attack on the xbru_dscheck.dd temporary file.
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Analysis
by VulDB Data Team • 11/15/2024
The vulnerability identified as CVE-2002-1512 represents a critical privilege escalation flaw within BRU Workstation 17.0, specifically affecting the xbru component. This issue stems from improper handling of temporary files during the execution of system checks, creating an exploitable race condition that local attackers can leverage to execute arbitrary code with elevated privileges. The vulnerability manifests when the xbru utility creates temporary files without proper security measures, allowing malicious users to manipulate the file system through symbolic link attacks.
The technical implementation of this vulnerability involves a classic symlink race condition attack pattern that aligns with CWE-377 and CWE-378, where insufficient file creation security measures enable attackers to substitute intended files with malicious alternatives. The xbru_dscheck.dd temporary file serves as the attack vector, as the application fails to validate the integrity of the temporary file path before using it. When the vulnerable application creates this temporary file without proper atomic operations or secure temporary file creation practices, it opens the door for local users to establish symbolic links that point to critical system files such as /etc/passwd or other privileged locations.
From an operational perspective, this vulnerability presents a severe threat to system integrity as it allows local attackers to escalate their privileges from standard user level to root access. The attack requires minimal privileges initially, as any local user can potentially exploit this weakness, but the consequences are significant since successful exploitation results in complete system compromise. The vulnerability impacts the availability, confidentiality, and integrity of the affected system, as attackers can modify critical system files, create backdoors, or establish persistent access mechanisms. The attack methodology follows established patterns documented in the MITRE ATT&CK framework under privilege escalation techniques, specifically targeting the use of insecure temporary file handling as a means to gain elevated privileges.
The remediation approach for this vulnerability requires immediate implementation of secure temporary file creation practices, including the use of proper file permissions, atomic file creation methods, and validation of file paths before use. System administrators should implement the principle of least privilege and ensure that temporary file operations are conducted with appropriate security controls. The fix involves modifying the xbru utility to use secure temporary file creation functions that prevent symbolic link attacks, such as creating temporary files with restrictive permissions and ensuring atomic operations. Additionally, regular security audits should verify that all system components properly handle temporary files and avoid predictable naming schemes that could be exploited by attackers. Organizations should also implement monitoring for suspicious file system activities and consider implementing file integrity monitoring solutions to detect unauthorized modifications to critical system files.