CVE-2002-0497 in mtr
Summary
by MITRE
Buffer overflow in mtr 0.46 and earlier, when installed setuid root, allows local users to access a raw socket via a long MTR_OPTIONS environment variable.
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Analysis
by VulDB Data Team • 06/19/2024
The vulnerability described in CVE-2002-0497 represents a classic buffer overflow flaw in the mtr network diagnostic tool version 0.46 and earlier. This issue occurs when mtr is installed with setuid root permissions, creating a dangerous privilege escalation vector. The vulnerability specifically manifests through the MTR_OPTIONS environment variable which is processed without proper bounds checking, allowing attackers to overflow the allocated buffer space.
This buffer overflow vulnerability falls under the CWE-121 category of Stack-based Buffer Overflow, where insufficient bounds checking allows an attacker to overwrite adjacent memory locations. The flaw is particularly dangerous because mtr typically runs with elevated privileges due to its setuid root configuration, which is necessary for its core functionality of creating raw network sockets. When a local user manipulates the MTR_OPTIONS environment variable with excessive input, the program fails to validate the length of the input before copying it into a fixed-size buffer, leading to memory corruption.
The operational impact of this vulnerability extends beyond simple privilege escalation as it provides attackers with direct access to raw socket capabilities that are normally restricted to root users. This access enables potential network reconnaissance, packet sniffing, and other malicious activities that could compromise network security. The vulnerability is particularly concerning in multi-user environments where local users might exploit this flaw to gain unauthorized access to network monitoring capabilities. The setuid root installation pattern means that any successful exploitation directly grants the attacker root privileges, making this a critical security concern for systems where mtr is deployed with elevated permissions.
Mitigation strategies should focus on both immediate patching and configuration changes. The most effective solution involves upgrading to mtr version 0.47 or later where the buffer overflow has been addressed through proper input validation and bounds checking. System administrators should also consider removing the setuid bit from mtr installations when possible, as this eliminates the privilege escalation aspect of the vulnerability. Additionally, implementing proper environment variable sanitization and monitoring for unusual MTR_OPTIONS usage patterns can help detect potential exploitation attempts. From an operational security perspective, this vulnerability aligns with ATT&CK technique T1068 which covers privilege escalation through local exploits, and T1046 which involves network service scanning. Organizations should conduct comprehensive vulnerability assessments to identify all instances of mtr with setuid root permissions and ensure proper patch management protocols are in place to prevent similar issues in other network diagnostic tools.