Description

IBM AIX 7.2, and 7.3 and IBM PowerVM VIOS 4.1 could allow a remote authenticated attacker to execute arbitrary code due to a stack-based buffer overflow.

Executive Summary

Technical Details

Mitigations

References

Additional Metadata

{
  "score": "8.8",
  "pubDate": "2026-08-19T20:17:08.937Z",
  "pubdate": "2026-08-19T20:17:08.937Z",
  "executiveSummary": "A stack-based buffer overflow vulnerability has been identified in IBM AIX 7.2, IBM AIX 7.3, and IBM PowerVM VIOS 4.1. This security flaw enables a remote authenticated attacker to execute arbitrary code on the underlying operating system and virtualization infrastructure.\nThe vulnerability poses a severe risk to confidentiality, integrity, and availability. Successful exploitation compromises the entire host operating system or Virtual I/O Server partition, allowing unauthorized users to execute arbitrary payloads with elevated privileges.\nExploitation of this vulnerability requires the attacker to possess authenticated access to the target system. The attack vector relies on supplying maliciously crafted input that exceeds allocated stack buffer boundaries, leading to memory corruption and subsequent control flow hijacking.\nOrganizations utilizing the affected IBM AIX and PowerVM VIOS versions face potential system compromise, privilege escalation, and lateral movement within virtualized environments if unmitigated.",
  "technicalDetails": "The vulnerability is classified as a stack-based buffer overflow, residing within the memory management handling of the affected products. Specifically, the vulnerable component fails to adequately validate the length of user-supplied data prior to copying it into a fixed-length memory buffer allocated on the call stack.\nThe root cause stems from unsafe memory copy operations where bounds checking is either missing or insufficiently implemented. When an attacker submits input that exceeds the expected size threshold, the excess data overflows the boundary of the stack buffer, overwriting adjacent stack memory structures, including saved frame pointers and return addresses.\nExploitation of this flaw requires the attacker to have valid authentication credentials on the target system. Upon establishing an authenticated session, the attacker interacts with the vulnerable interface or service by transmitting a specially crafted payload designed to corrupt the execution stack.\nDuring the attack flow, the oversized input fills the target buffer and overwrites the saved return address with a manipulated pointer value. When the vulnerable function attempts to return execution control to its caller, the instruction pointer is redirected to the attacker-supplied payload or memory location, facilitating arbitrary code execution within the context of the running process.\nThe affected software versions include IBM AIX 7.2, IBM AIX 7.3, and IBM PowerVM VIOS 4.1. The privilege level associated with the execution of arbitrary code depends on the privileges of the vulnerable process handling the input, which frequently leads to local privilege escalation or full system compromise given the privileged nature of AIX kernel and VIOS management routines.\nPost-exploitation impact includes complete administrative control over the affected AIX partition or PowerVM VIOS instance, potential escape or interference with hosted virtual machines, unauthorized modification of system configurations, and extraction of sensitive data."
}