Description

IBM AIX 7.2, and 7.3 and IBM PowerVM VIOS 4.1 could allow a local attacker to execute arbitrary code due to improperly scrubbed environment variables.

Executive Summary

Technical Details

Mitigations

References

Additional Metadata

{
  "score": "7.8",
  "pubDate": "2026-08-19T20:17:08.120Z",
  "pubdate": "2026-08-19T20:17:08.120Z",
  "executiveSummary": "A local privilege escalation vulnerability exists within IBM AIX 7.2, 7.3, and IBM PowerVM VIOS 4.1, stemming from improperly scrubbed environment variables.\nThis vulnerability allows an authenticated local attacker to execute arbitrary code with elevated privileges, bypassing intended security boundaries.\nThe root cause lies in the improper sanitization or handling of environment variables passed to privileged execution contexts, enabling attackers to manipulate runtime behavior and inject malicious payloads or shared library paths.\nSuccessful exploitation requires local access to the target system and appropriate authentication, but no advanced network exposure is necessary.\nThe resulting impact includes unauthorized code execution, potential compromise of system integrity, and full system takeover within the affected logical partitions or hypervisor environment.\nOrganizations utilizing the specified IBM AIX and PowerVM VIOS versions face significant risk if unprivileged users can interact with vulnerable SUID/SGID binaries or privileged daemons that fail to validate environment parameters adequately.",
  "technicalDetails": "The vulnerability resides in the runtime environment handling mechanisms of IBM AIX 7.2, 7.3, and IBM PowerVM VIOS 4.1, specifically involving the lack of proper environment variable scrubbing prior to executing privileged operations.\nWhen a privileged binary, SUID/SGID program, or system daemon executes, it inherits environment variables from the calling unprivileged process.\nIf the application fails to sanitize or strip security-sensitive variables—such as those controlling dynamic linker paths (e.g., LIBPATH or equivalent runtime loader directives)—an attacker can manipulate these variables to point to malicious shared libraries or control execution flow.\nThe attack flow begins with a local, authenticated attacker preparing a malicious payload or custom shared library within a user-accessible directory.\nThe attacker then sets specific environment variables in their local shell environment to override default system paths or runtime configurations.\nUpon invoking a vulnerable local executable, the application processes the tainted environment variables without adequate validation or restriction.\nThe dynamic linker or runtime engine loads the attacker-supplied library or executes instructions based on the manipulated runtime parameters, bypassing standard access controls.\nBecause the execution context inherits the privileges of the targeted binary or daemon, the malicious payload executes with elevated privileges.\nPost-exploitation impact includes full local privilege escalation, unauthorized access to sensitive system resources, manipulation of operating system configurations, and potential persistence across the affected IBM AIX or PowerVM VIOS environment."
}