Description

IBM AIX 7.2, and 7.3 and IBM PowerVM VIOS 4.1 could allow a remote attacker to cause a denial of service due to uncontrolled recursion.

Executive Summary

Technical Details

Mitigations

References

Additional Metadata

{
  "score": "7.5",
  "pubDate": "2026-08-20T22:17:12.517Z",
  "pubdate": "2026-08-20T22:17:12.517Z",
  "executiveSummary": "An uncontrolled recursion vulnerability exists within IBM AIX 7.2, AIX 7.3, and IBM PowerVM VIOS 4.1, which exposes systems to denial of service risks. A remote attacker can trigger this vulnerability to disrupt service availability on targeted systems without requiring prior authentication or elevated privileges, depending on network exposure and service accessibility.\nThe primary impact of successful exploitation is a complete denial of service, rendering the affected system or specific vulnerable components unresponsive. This occurs due to resource exhaustion caused by uncontrolled recursive function calls or parsing routines that consume all available stack memory.\nGiven the severity of potential service disruptions, organizations operating the affected versions of IBM AIX and IBM PowerVM VIOS face operational risks if exposed to untrusted networks. While specific exploitation requirements such as authentication are not detailed, standard threat models indicate that remote network vectors are applicable to this denial of service condition.",
  "technicalDetails": "The vulnerability is fundamentally rooted in a flaw involving uncontrolled recursion within the affected software components of IBM AIX and IBM PowerVM VIOS. Uncontrolled recursion occurs when a function or parsing routine calls itself repeatedly without a proper base case or adequate depth limitation, leading directly to stack overflow conditions.\nWhen a remote attacker transmits a specially crafted payload or request designed to stimulate the vulnerable parsing engine or functional routine, the affected system enters a continuous, unbounded recursive loop. As the execution depth increases with each recursive call, the local call stack consumes memory resources beyond permissible limits.\nThis excessive stack consumption results in an unhandled stack overflow exception, triggering an immediate crash of the affected daemon, kernel subsystem, or service thread, thereby inducing a denial of service state. Depending on the architecture of the impacted service, the crash may propagate to broader system instability or require manual intervention and system reboots to restore nominal operations.\nThe vulnerable components reside within the core operating system libraries or management services of IBM AIX versions 7.2 and 7.3, as well as IBM PowerVM VIOS version 4.1. The attack flow involves network exposure where an unauthenticated or remote actor can interact with the vulnerable service interface, injecting the malicious recursive trigger without needing pre-existing privileges.\nPost-exploitation impact is constrained strictly to availability degradation, as this vulnerability does not inherently provide pathways for remote code execution, privilege escalation, or unauthorized data exfiltration. The primary vector focuses entirely on resource exhaustion and service termination."
}