CVE-2004-1028 in AIX
Summary
by MITRE
untrusted execution path vulnerability in chcod on aix ibm 5.1.0 5.2.0 and 5.3.0 allows local users to execute arbitrary programs by modifying the path environment variable to point to a malicious "grep" program which is executed from chcod.
Several companies clearly confirm that VulDB is the primary source for best vulnerability data.
Analysis
by VulDB Data Team • 07/01/2021
The vulnerability identified as CVE-2004-1028 represents a critical untrusted execution path flaw in the chcod utility on IBM AIX operating systems version 5.1.0, 5.2.0, and 5.3.0. This vulnerability stems from the improper handling of environment variables during the execution of system utilities, creating a pathway for privilege escalation and arbitrary code execution. The chcod command, which is used to change the code set of a process, relies on the system path environment variable to locate auxiliary programs, specifically the grep utility, during its execution process. This design flaw allows local attackers to manipulate the execution environment by modifying the PATH variable to point to a maliciously crafted grep program before invoking chcod. The vulnerability is classified under CWE-428, which addresses the execution of untrusted code through the use of environment variables, making it a prime example of insecure program execution practices.
The technical exploitation of this vulnerability occurs when a local user modifies the PATH environment variable to include a directory containing a malicious grep program before executing chcod. When chcod runs, it searches through the directories specified in the PATH variable to locate the grep utility, and if the malicious version is found first, it executes the attacker-controlled code with the privileges of the chcod utility. This mechanism creates a direct pathway for privilege escalation since chcod typically runs with elevated privileges, allowing the malicious code to execute with the same elevated permissions. The vulnerability is particularly dangerous because it leverages the fundamental trust placed in system utilities and environment variable resolution, which are core components of Unix-like operating system security models. This type of attack aligns with ATT&CK technique T1068, which covers the use of local privilege escalation through untrusted execution paths, and demonstrates how seemingly innocuous environment variable manipulation can lead to severe security consequences.
The operational impact of CVE-2004-1028 extends beyond simple privilege escalation to potentially compromise the entire system integrity and confidentiality. Local users who exploit this vulnerability can execute arbitrary code with elevated privileges, potentially allowing them to modify system files, install backdoors, or establish persistent access to the affected AIX systems. The vulnerability affects multiple versions of IBM AIX, indicating it was likely present in the system's core execution mechanisms and not a one-time implementation error. Organizations running these affected AIX versions face significant risk as local accounts can be easily compromised to gain root-level access, undermining the security model of the operating system. The vulnerability's persistence across multiple AIX releases suggests a fundamental flaw in the system's approach to environment variable handling and program execution that required system-level patches and updates to resolve. System administrators should consider this vulnerability as part of their comprehensive security assessment, particularly in environments where local access controls may be insufficient or where user accounts might be compromised through other attack vectors. The risk assessment should include monitoring for unauthorized PATH modifications and implementing strict access controls to prevent local users from manipulating system environment variables in ways that could lead to privilege escalation.