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 a heap-based buffer overflow.

Executive Summary

Technical Details

Mitigations

References

Additional Metadata

{
  "score": "7.5",
  "pubDate": "2026-08-20T15:17:29.293Z",
  "pubdate": "2026-08-20T15:17:29.293Z",
  "executiveSummary": "This vulnerability involves a heap-based buffer overflow flaw affecting IBM AIX 7.2, IBM AIX 7.3, and IBM PowerVM VIOS 4.1. The flaw allows an unauthenticated remote attacker to trigger a denial of service condition against vulnerable systems.\nThe primary impact of successful exploitation is service disruption, causing the affected operating system or virtualization component to crash or become unresponsive. The vulnerability exposes core system availability to remote disruption over the network without requiring prior authentication or privileged access.\nThe risk implications are severe for environments utilizing these enterprise Unix and virtualization platforms, as a remote denial of service can disrupt critical business operations and dependent virtual machines managed by IBM PowerVM VIOS 4.1.\nAttacker capabilities are limited to causing denial of service conditions through heap memory corruption, as remote code execution parameters are not specified in the input description. Exploitation relies on network connectivity to the vulnerable service processing malformed inputs that exceed allocated heap buffer boundaries.",
  "technicalDetails": "The vulnerability is classified as a heap-based buffer overflow affecting IBM AIX 7.2, IBM AIX 7.3, and IBM PowerVM VIOS 4.1. The root cause stems from insufficient bounds checking when processing input data within a vulnerable component handling network communications or data parsing.\nWhen a remote attacker transmits a specially crafted, oversized payload to the target service running on the affected operating systems or virtualization environment, the input exceeds the pre-allocated boundaries of a heap-allocated buffer. This memory corruption overwrites adjacent heap structures, leading directly to abnormal program termination, memory access violations, and systemic denial of service.\nThe attack flow proceeds as follows: First, the remote attacker establishes network connectivity with the vulnerable service listening on the target IBM AIX or IBM PowerVM VIOS instance. Second, the attacker crafts a malicious payload designed to exceed the size constraints of the target heap buffer. Third, the attacker transmits this payload across the network protocol to the vulnerable component. Fourth, the application fails to validate the input length prior to copying it into the heap buffer, resulting in a heap-based buffer overflow. Finally, the resulting memory corruption crashes the targeted daemon, process, or kernel subsystem, culminating in a complete denial of service for the affected host.\nThe exploitation vector is network-exposed, requiring no prior authentication or administrative privileges. Affected versions explicitly include IBM AIX 7.2, IBM AIX 7.3, and IBM PowerVM VIOS 4.1. Post-exploitation impact is strictly contained to availability degradation and service crashes, disrupting system operations and dependent virtualized workloads."
}