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 a stack-based buffer overflow.

Executive Summary

Technical Details

Mitigations

References

Additional Metadata

{
  "score": "8.1",
  "pubDate": "2026-08-20T22:17:13.187Z",
  "pubdate": "2026-08-20T22:17:13.187Z",
  "executiveSummary": "A stack-based buffer overflow vulnerability has been identified in IBM AIX 7.2, 7.3, and IBM PowerVM VIOS 4.1. This vulnerability allows a remote attacker to execute arbitrary code on the underlying operating system or virtualization layer.\nThe flaw stems from improper boundary checking during the processing of input data, leading to a stack-based buffer overflow condition. If successfully exploited, an unauthorized remote adversary can corrupt memory structures, overwrite stack frames, and hijack control flow to execute malicious payloads with the privileges of the vulnerable service.\nThe risk implication is critical, as successful exploitation compromises the confidentiality, integrity, and availability of affected systems, potentially granting full system access to the attacker.\nExploitation requires network connectivity to the vulnerable service handling the improperly bounded input. No specific authentication requirements are explicitly detailed, but remote reachability to the vulnerable component is a prerequisite for attack execution.",
  "technicalDetails": "The vulnerability is classified as a stack-based buffer overflow residing within the affected components of IBM AIX 7.2, 7.3, and IBM PowerVM VIOS 4.1.\nThe root cause of the vulnerability is the lack of rigorous input validation and boundary enforcement when handling incoming data streams within the vulnerable parsing routines or network-facing daemons.\nDuring typical execution, the affected component accepts input parameters without verifying whether the data size exceeds the allocated buffer bounds on the call stack.\nWhen a remote attacker transmits a specially crafted, oversized payload to the target service, the excessive data overflows the fixed-size stack buffer.\nThis overflow overwrites adjacent stack memory, including critical execution context data such as saved frame pointers and return addresses.\nBy carefully structuring the malicious payload, the attacker can manipulate the overwritten return address to point to malicious shellcode injected into the stack or pivot execution to existing executable instructions via techniques such as return-oriented programming (ROP).\nUpon function return, the CPU loads the attacker-controlled address into the instruction pointer, transferring execution control directly to the payload.\nThe attack flow proceeds as follows: 1) The attacker identifies the network exposure of the vulnerable service running on IBM AIX or IBM PowerVM VIOS. 2) The attacker crafts a malicious sequence containing exploit code and a manipulated return address designed to trigger the stack overflow. 3) The attacker transmits the payload over the network to the target. 4) The application processes the input without bounds checking, resulting in memory corruption. 5) Control flow hijacking occurs, resulting in arbitrary code execution.\nThe impact of successful exploitation includes complete system compromise, allowing the attacker to execute arbitrary commands, install persistent backdoors, escalate privileges if initial execution occurs in a restricted context, or pivot deeper into the network infrastructure."
}