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 an improper check for an array index boundary.

Executive Summary

Technical Details

Mitigations

References

Additional Metadata

{
  "score": "4.3",
  "pubDate": "2026-08-19T20:17:06.457Z",
  "pubdate": "2026-08-19T20:17:06.457Z",
  "executiveSummary": "This vulnerability involves an improper check for an array index boundary within IBM AIX 7.2, 7.3, and IBM PowerVM VIOS 4.1. The flaw allows a remote attacker to induce a denial of service condition on target systems. The root cause stems from a failure to properly validate array indices before memory access operations, which can lead to out-of-bounds reads or writes, resulting in application crashes, kernel panics, or system-wide instability. The primary security impact is availability degradation or complete service disruption of the affected operating system or hypervisor environment. The vulnerability poses significant risk implications for enterprise infrastructures relying on these platforms for mission-critical virtualization and workload management. Exploitation requires network access to the vulnerable service, and depending on the specific attack vector, may be executed remotely without prior authentication or privileged access. Mitigation requires applying the appropriate vendor-supplied security fixes and maintaining strict network segmentation to limit exposure of susceptible network services.",
  "technicalDetails": "The vulnerability resides in the core components of IBM AIX 7.2, 7.3, and IBM PowerVM VIOS 4.1, specifically within routines that handle network protocols, system calls, or data parsing mechanisms where internal array structures are populated or referenced based on external input. The root cause of the vulnerability is an insufficient bounds check on array indices derived from untrusted input. When a remote attacker supplies a specially crafted payload containing manipulated index values, the affected subsystem fails to validate whether the index falls within the allocated boundaries of the target array. Consequently, the execution context performs memory operations outside the intended buffer allocation. Depending on the memory layout and the specific function handling the out-of-bounds condition, the attack flow initiates when the vulnerable component processes malicious network packets or input data streams. The lack of proper validation leads to memory corruption, invalid memory access exceptions, or unauthorized access to adjacent memory regions. In the context of the operating system kernel or the PowerVM Virtual I/O Server (VIOS), such memory anomalies typically trigger an immediate system crash or kernel panic, terminating all running virtual machines and hosted applications to prevent further corruption. The vulnerability is accessible over the network, allowing remote threat actors to trigger the condition without local system access. Authentication and elevated privileges are generally not required to initiate the disruptive payload delivery, provided the vulnerable network-exposed service accepts the malformed input. Post-exploitation impact is primarily focused on denial of service, as the resulting system crash halts operational continuity, requiring physical or out-of-band administrative intervention to restore service availability."
}