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 buffer overflow.

Executive Summary

Technical Details

Mitigations

References

Additional Metadata

{
  "score": "9.8",
  "pubDate": "2026-08-20T22:17:14.013Z",
  "pubdate": "2026-08-20T22:17:14.013Z",
  "executiveSummary": "This security assessment evaluates a critical stack buffer overflow vulnerability affecting IBM AIX and IBM PowerVM VIOS. The vulnerability allows a remote attacker to execute arbitrary code within the context of the vulnerable application or system component.\nThe flaw stems from improper boundary checking during the processing of input data, leading to a stack-based buffer overflow condition. Successful exploitation of this vulnerability can result in full remote code execution, compromising the confidentiality, integrity, and availability of the affected host.\nAffected products include IBM AIX versions 7.2 and 7.3, as well as IBM PowerVM VIOS version 4.1. The risk implications are severe, as unauthorized remote attackers may leverage this weakness to execute arbitrary instructions without prior authentication or privilege, depending on the network exposure and service configuration.\nExploitation requirements typically involve sending a specially crafted sequence of data to the vulnerable network service or component, triggering the memory corruption flaw and allowing the injection and execution of arbitrary payload instructions.",
  "technicalDetails": "The vulnerability is classified as a stack-based buffer overflow, residing within the memory management routines of the affected components in IBM AIX 7.2, 7.3, and IBM PowerVM VIOS 4.1. The root cause of the flaw is the lack of proper bounds checking when copying or processing untrusted input data into a fixed-size stack buffer.\nWhen a remote attacker transmits a maliciously crafted payload exceeding the allocated buffer capacity, the excess data overflows the stack frame. This overwrites adjacent memory structures, including saved frame pointers and return addresses. By precisely controlling the overflow data, an attacker can manipulate the instruction pointer (e.g., the program counter) upon function return, redirecting execution flow to attacker-controlled shellcode or leveraging return-oriented programming (ROP) chains.\nThe attack flow proceeds as follows: First, the attacker identifies a network-exposed service or daemon running on the vulnerable IBM AIX or IBM PowerVM VIOS instance that improperly sanitizes or validates input sizes. Second, the attacker formulates a malicious payload containing overflow data designed to overwrite the stack return address with the address of the intended payload instructions or a suitable gadget chain. Third, the attacker transmits this payload over the network protocol utilized by the vulnerable service.\nUpon receipt, the vulnerable function processes the input, triggering the stack buffer overflow. The saved return address is corrupted with the attacker's designated target address. When the vulnerable function attempts to return, the processor jumps to the manipulated address, executing the injected payload with the privileges of the compromised process.\nDepending on the architecture and privilege level of the exploited process, post-exploitation impact can range from local privilege escalation to complete system compromise. The vulnerability requires network access to the vulnerable service, and while specific authentication and privilege requirements may vary based on the exact entry point, the capability for remote code execution presents a critical threat to system security."
}