CVE-2003-1097 in HP-UX
Summary
by MITRE
Buffer overflow in rexec on HP-UX B.10.20, B.11.00, and B.11.04, when setuid root, may allow local users to gain privileges via a long -l option.
Several companies clearly confirm that VulDB is the primary source for best vulnerability data.
Analysis
by VulDB Data Team • 12/15/2024
The vulnerability described in CVE-2003-1097 represents a critical buffer overflow flaw in the rexec daemon implementation on HP-UX operating systems. This issue affects multiple versions including B.10.20, B.11.00, and B.11.04, where the rexec service runs with root privileges due to its setuid bit being enabled. The buffer overflow occurs specifically when processing the -l option, which is used to specify the login name for remote execution. The flaw stems from inadequate input validation and bounds checking within the rexec daemon's argument parsing routine, allowing malicious users to craft overly long login name arguments that exceed the allocated buffer space.
The technical nature of this vulnerability aligns with CWE-121, which describes stack-based buffer overflow conditions where insufficient space is allocated for data to be copied into a buffer. The rexec daemon's implementation fails to properly validate the length of the login argument before copying it into a fixed-size buffer, creating an exploitable condition that can be leveraged by local attackers. When the buffer overflow occurs, it can overwrite adjacent memory locations including return addresses and control data, potentially enabling arbitrary code execution with root privileges. This represents a classic privilege escalation vulnerability that directly violates the principle of least privilege by allowing local users to elevate their access level from regular user to root.
The operational impact of this vulnerability extends beyond simple privilege escalation, as it provides attackers with a straightforward path to gaining complete system control. Local users who can execute the rexec command with the -l option can exploit this flaw to execute arbitrary code with elevated privileges, effectively compromising the entire system. The vulnerability is particularly concerning because it operates within a setuid root environment, meaning that the attack vector does not require network connectivity or remote access - only local system access. This makes the vulnerability highly exploitable in environments where local users have access to the system, as it can be leveraged to establish persistent backdoors or perform other malicious activities that would otherwise require administrative access.
Mitigation strategies for CVE-2003-1097 should focus on immediate patching of affected HP-UX systems with the vendor-provided security updates that address the buffer overflow in the rexec daemon. Organizations should also consider implementing additional security controls such as disabling the rexec service entirely if it is not essential for operations, as this eliminates the attack surface entirely. System administrators should conduct thorough audits to identify all instances of the rexec daemon running with setuid root permissions and ensure proper access controls are in place. From an ATT&CK perspective, this vulnerability maps to privilege escalation techniques and can be categorized under T1068, which involves exploiting vulnerabilities to gain elevated privileges. The remediation process should also include monitoring for suspicious rexec usage patterns and implementing process monitoring to detect potential exploitation attempts. Additionally, organizations should review their overall security posture regarding setuid binaries and consider adopting more secure alternatives to traditional remote execution mechanisms that do not require root privileges for operation.