CVE-2001-1080 in AIX
Summary
by MITRE
diagrpt in AIX 4.3.x and 5.1 uses the DIAGDATADIR environment variable to find and execute certain programs, which allows local users to gain privileges by modifying the variable to point to a Trojan horse program.
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Analysis
by VulDB Data Team • 06/05/2024
The vulnerability described in CVE-2001-1080 resides within the diagrpt utility on IBM AIX operating systems version 4.3.x and 5.1. This diagnostic reporting tool is designed to collect and display system information for troubleshooting purposes. The flaw manifests in how diagrpt handles the DIAGDATADIR environment variable, which serves as a critical configuration parameter for locating diagnostic data files and executable components. When the system processes diagnostic reports, it relies on this environment variable to determine where to search for specific programs and data files necessary for the diagnostic process.
The technical implementation of this vulnerability stems from improper handling of environment variables within the diagrpt utility. The diagnostic reporting tool directly incorporates the value of DIAGDATADIR into its execution path without adequate validation or sanitization of the variable contents. This creates a classic privilege escalation vector where a local attacker can manipulate the environment variable to redirect the utility's execution flow toward malicious programs. The vulnerability operates under CWE-78, which specifically addresses Improper Neutralization of Special Elements used in OS Command, as the environment variable is treated as a command execution parameter rather than being properly validated.
The operational impact of this vulnerability is significant for systems running affected AIX versions, as it enables local users to achieve privilege escalation from their current user context to the root level. Attackers can exploit this weakness by creating a Trojan horse program in a location of their choosing and then modifying the DIAGDATADIR environment variable to point to that malicious executable. When diagrpt executes with elevated privileges, it will run the attacker-controlled program with root permissions, effectively providing complete system compromise. This vulnerability aligns with ATT&CK technique T1068, which covers the use of local privilege escalation techniques through environment variable manipulation, and T1548.001, which addresses privilege escalation through the use of setuid binaries.
The exploitation process requires local system access but does not need network connectivity or special prerequisites beyond basic user privileges. The attack vector is particularly dangerous because it leverages legitimate system tools and does not require sophisticated attack techniques. Organizations with multiple users or shared systems are particularly vulnerable, as any user with access to the system can potentially exploit this weakness. System administrators should note that the vulnerability affects the diagnostic reporting functionality specifically, making it more difficult to detect through standard security monitoring. The recommended mitigation strategy involves either patching the affected AIX versions or implementing strict environment variable controls to prevent modification of DIAGDATADIR by non-privileged users. Additionally, system administrators should consider restricting access to the diagrpt utility and monitoring for unauthorized changes to critical environment variables as part of their overall security posture.