Description

IBM AIX 7.2, and 7.3 and IBM PowerVM VIOS 4.1 could allow a remote attacker to execute arbitrary code due to an off-by-one error in bounds checking.

Executive Summary

Technical Details

Mitigations

References

Additional Metadata

{
  "score": "8.8",
  "pubDate": "2026-08-19T20:17:10.840Z",
  "pubdate": "2026-08-19T20:17:10.840Z",
  "executiveSummary": "This vulnerability is an off-by-one error in bounds checking affecting IBM AIX 7.2, 7.3, and IBM PowerVM VIOS 4.1. The security flaw allows a remote attacker to execute arbitrary code on vulnerable systems.\nThe primary impact of successful exploitation is complete system compromise, enabling unauthorized actors to execute arbitrary code with the privileges of the affected service.\nThe affected products include IBM AIX versions 7.2 and 7.3, as well as IBM PowerVM VIOS version 4.1. This presents significant risk implications for enterprise environments relying on these operating systems and virtualization platforms.\nAn attacker must possess network connectivity to the target service to exploit this vulnerability remotely. The root cause stems from improper bounds checking logic, specifically an off-by-one error during memory operations.\nNo specific authentication or advanced privileges are explicitly stated as prerequisites beyond network reachability, highlighting the severity of remote code execution exposures in core OS components and hypervisor virtualization environments.",
  "technicalDetails": "The vulnerability is rooted in an off-by-one error occurring during bounds checking within affected components of IBM AIX 7.2, 7.3, and IBM PowerVM VIOS 4.1.\nAn off-by-one error typically manifests when a buffer allocation or indexing operation calculates size or boundary limits incorrectly, allowing a loop or copy operation to read or write exactly one byte or element beyond the allocated buffer boundaries.\nIn the context of this vulnerability, the flaw in bounds validation logic during memory handling permits malicious manipulation of adjacent memory structures. When the affected routine processes maliciously crafted network inputs, the off-by-one condition can corrupt adjacent heap or stack metadata, function pointers, or control flow variables.\nThe attack flow begins with a remote attacker transmitting a specially crafted payload across the network to the vulnerable service running on IBM AIX or IBM PowerVM VIOS. Upon reception, the vulnerable component attempts to parse or process the input using routines that contain flawed bounds checking.\nAs the application performs memory operations, the off-by-one boundary calculation allows data to overwrite adjacent memory regions. By carefully engineering the input payload, an attacker can manipulate this precise memory corruption to redirect execution flow.\nPost-exploitation impact includes the execution of arbitrary machine instructions supplied within the attacker's payload. Depending on the execution context and privileges of the vulnerable process, this can result in full remote code execution, unauthorized escalation of privileges, and complete compromise of the underlying operating system or virtual input/output server environment.\nAffected software versions include IBM AIX 7.2, IBM AIX 7.3, and IBM PowerVM VIOS 4.1. Network exposure is present due to the remote nature of the attack vector, permitting exploitation without localized physical access."
}