Description

IBM AIX 7.2, and 7.3 and IBM PowerVM VIOS 4.1 has a vulnerability in cmdnim that may allow an unprivileged local user to executes the payload as root.

Executive Summary

Technical Details

Mitigations

References

Additional Metadata

{
  "score": "8.8",
  "pubDate": "2026-08-20T22:17:18.613Z",
  "pubdate": "2026-08-20T22:17:18.613Z",
  "executiveSummary": "A local privilege escalation vulnerability exists in IBM AIX 7.2, 7.3, and IBM PowerVM VIOS 4.1 affecting the cmdnim component. The vulnerability arises from insecure command execution handling within the utility, enabling an unprivileged local attacker to execute arbitrary payloads with root privileges.\nThe primary impact of this security flaw is complete system compromise. By leveraging local access, a threat actor can bypass standard access controls and execute administrative instructions, leading to a total loss of confidentiality, integrity, and availability on the affected operating system or Virtual I/O Server (VIOS) instance.\nThe affected products include IBM AIX versions 7.2 and 7.3, alongside IBM PowerVM VIOS version 4.1. The risk implications are severe for enterprise environments utilizing these UNIX-based operating systems, particularly in shared hosting or multi-tenant configurations where local user isolation is critical.\nExploitation requirements dictate that the attacker must already possess unprivileged local shell access to the target host. No remote network vector is required for initial exploitation. Once local access is established, the attacker can interact directly with the vulnerable cmdnim binary to trigger the execution flow anomaly and elevate privileges to root.",
  "technicalDetails": "The vulnerability resides within the cmdnim component of IBM AIX 7.2, 7.3, and IBM PowerVM VIOS 4.1. The root cause stems from improper validation and handling of user-supplied inputs or environmental parameters passed to the utility during execution, which facilitates local privilege escalation.\nAuthentication requirements are minimal, as the attack can be initiated by any unprivileged local user possessing valid shell access to the underlying system. The network exposure is strictly local; the flaw cannot be exploited remotely over a network protocol without prior local system access.\nThe attack flow proceeds as follows: First, the unprivileged local user prepares a malicious payload designed to execute arbitrary system commands. Second, the user invokes the vulnerable cmdnim component while supplying manipulated parameters or environment variables intended to hijack the execution context. Third, due to insufficient input sanitation and improper privilege management within the binary, the application executes the supplied routine or payload within the security context of the superuser.\nThe payload behavior involves running arbitrary OS commands or scripts with full root privileges. The post-exploitation impact includes unauthorized modification of system files, creation of persistent administrative backdoors, access to sensitive cryptographic material or configuration data, and complete administrative control over the affected IBM AIX or IBM PowerVM VIOS environment."
}