CVE-2003-1099 in HP-UX
Summary
by MITRE
shar on HP-UX B.11.00, B.11.04, and B.11.11 creates temporary files with predictable names in /tmp, which allows local users to cause a denial of service and possibly execute arbitrary code via a symlink attack.
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Analysis
by VulDB Data Team • 12/15/2024
The vulnerability described in CVE-2003-1099 affects the shar utility on HP-UX operating systems versions B.11.00, B.11.04, and B.11.11. This flaw represents a classic insecure temporary file creation issue that has significant implications for system security and availability. The shar utility, which is used to create shell archive files for distributing software packages, demonstrates poor security practices by generating temporary files with predictable naming conventions in the /tmp directory. This predictable naming behavior creates a race condition vulnerability that can be exploited by local attackers to manipulate the system's temporary file environment.
The technical flaw stems from the shar utility's implementation of temporary file creation without proper randomization or secure naming mechanisms. When shar processes archive files, it creates temporary files in the /tmp directory using predictable names that an attacker can anticipate. This design flaw directly violates security best practices and creates opportunities for privilege escalation and denial of service attacks. The vulnerability is particularly dangerous because it allows local users to craft symbolic links that can interfere with the temporary file creation process, potentially leading to arbitrary code execution with elevated privileges.
From an operational impact perspective, this vulnerability enables local attackers to cause system instability through denial of service conditions while simultaneously providing a potential pathway for privilege escalation. The symlink attack mechanism allows attackers to replace intended temporary files with malicious counterparts, which can then be executed during the normal operation of the shar utility. This creates a scenario where a local user can effectively compromise system integrity and availability, as the temporary file race condition can be exploited to execute arbitrary code with the privileges of the user running the shar utility. The vulnerability's impact extends beyond simple denial of service, as it represents a potential backdoor for persistent system compromise.
The security implications of this vulnerability align with CWE-377, which addresses insecure temporary file creation practices, and can be mapped to ATT&CK technique T1059 for privilege escalation through command execution. Organizations running affected HP-UX systems should immediately implement mitigations including updating to patched versions of the shar utility, implementing proper file permissions for the /tmp directory, and monitoring for suspicious symbolic link creation patterns. System administrators should also consider restricting access to the shar utility for non-privileged users and implementing additional security controls such as file integrity monitoring to detect potential exploitation attempts. The vulnerability demonstrates the critical importance of secure temporary file handling practices in system utilities and the potential consequences when such practices are not properly implemented.