CVE-2008-1710 in AIX
Summary
by MITRE
Untrusted search path vulnerability in chnfsmnt in IBM AIX 6.1 allows local users to gain privileges via a modified PATH environment variable.
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Analysis
by VulDB Data Team • 04/13/2019
The vulnerability identified as CVE-2008-1710 represents a classic untrusted search path issue affecting the chnfsmnt utility within IBM AIX 6.1 operating system. This flaw resides in the way the system handles environment variables, specifically the PATH variable that determines the order in which executable files are searched during program execution. The chnfsmnt utility, which is responsible for managing file system mounts in AIX environments, fails to properly validate or sanitize the PATH environment variable before using it to locate required system binaries. This weakness creates an exploitable condition where a local attacker can manipulate the execution flow by inserting malicious binaries into directories that are searched before legitimate system utilities.
The technical exploitation of this vulnerability occurs when a local user modifies the PATH environment variable to place attacker-controlled directories at the beginning of the search order. When chnfsmnt executes and searches for supporting utilities, it will first find and execute the malicious binaries instead of the legitimate system counterparts. This privilege escalation vector allows attackers to execute code with elevated privileges, potentially gaining root access to the system. The vulnerability is classified under CWE-426 as an Untrusted Search Path, which specifically addresses the risk of executing unintended programs when the system searches for executables in untrusted locations. This type of flaw directly maps to techniques described in the MITRE ATT&CK framework under T1068 for Exploitation for Privilege Escalation, where adversaries leverage weaknesses in program execution to elevate their privileges.
The operational impact of this vulnerability extends beyond simple privilege escalation as it provides attackers with persistent access to the compromised system. Once elevated, attackers can modify system configurations, install backdoors, or exfiltrate sensitive data without detection. The vulnerability affects all versions of IBM AIX 6.1 where chnfsmnt is present, making it particularly concerning for enterprise environments that rely on AIX for critical operations. Organizations running these systems face potential data breaches, system compromise, and loss of integrity in their file system management processes. The local nature of the attack means that physical access or existing user credentials are sufficient to exploit the vulnerability, making it particularly dangerous in environments where user access controls are not properly enforced.
Mitigation strategies for CVE-2008-1710 should focus on both immediate system hardening and long-term security improvements. System administrators should ensure that the PATH environment variable is properly configured to avoid including untrusted directories, particularly those writable by non-privileged users. The chnfsmnt utility should be updated with proper environment variable sanitization to prevent the exploitation of untrusted search paths. Security policies should enforce that PATH variables are set to trusted directories only, with explicit checks against writable locations. Additionally, implementing mandatory access controls and regular security auditing of environment variable configurations can help detect and prevent such vulnerabilities. Organizations should also consider applying the relevant IBM AIX security patches that address this specific vulnerability, as IBM has issued updates to correct the untrusted search path implementation in the affected utilities. The remediation process should include comprehensive system reviews to identify other utilities that might be susceptible to similar vulnerabilities, ensuring that all system binaries properly validate their execution environment to prevent privilege escalation attacks.