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 improper validation of an array size field.

Executive Summary

Technical Details

Mitigations

References

Additional Metadata

{
  "score": "7.5",
  "pubDate": "2026-08-20T22:17:14.540Z",
  "pubdate": "2026-08-20T22:17:14.540Z",
  "executiveSummary": "A denial of service vulnerability has been identified in IBM AIX and IBM PowerVM VIOS, specifically impacting versions 7.2, 7.3, and 4.1 respectively. The vulnerability stems from improper validation of an array size field within the affected software components, allowing a remote attacker to trigger application instability or system crashes.\nThe primary impact of successful exploitation is a complete denial of service against the targeted system, disrupting critical operational services and workloads hosted on the affected logical partitions or Virtual I/O Servers.\nRisk implications remain high for enterprise environments relying on these platforms due to the potential for unauthenticated remote disruption. Attacker capabilities involve remote network-based exploitation vectors to send maliciously crafted network or inter-process communications containing invalid array bounds.\nExploitation requirements rely on network connectivity to the vulnerable service parsing the malformed array size data, without necessarily requiring prior authentication or elevated privileges depending on the specific network exposure of the vulnerable vector.",
  "technicalDetails": "The root cause of the vulnerability lies in insufficient boundary checks and input validation regarding an array size field processed by the underlying software components of IBM AIX 7.2, IBM AIX 7.3, and IBM PowerVM VIOS 4.1.\nWhen the vulnerable component parses incoming data containing a manipulated or excessively large array size parameter, it fails to verify that the specified size aligns with allocated memory buffers or structural constraints.\nThe exploitation method involves a remote attacker transmitting a maliciously crafted payload over the network to the vulnerable service. This payload specifies an incongruous array size value designed to induce out-of-bounds memory referencing, integer overflows, or memory exhaustion.\nThe attack flow proceeds as follows: First, the attacker identifies the network service or daemon responsible for parsing the specific protocol or data structure containing the vulnerable array size field. Second, the attacker formulates a payload where the array size field is manipulated outside expected operational parameters. Third, the attacker transmits this payload to the target endpoint. Fourth, upon parsing, the receiving routine attempts to allocate memory or iterate based on the unvalidated array size, resulting in a segmentation fault, kernel panic, or abnormal termination of the critical service.\nThe vulnerable component comprises the internal data parsing and memory management routines handling specific network protocols or control messages within the affected operating systems and virtualization layers.\nAffected versions include IBM AIX 7.2, IBM AIX 7.3, and IBM PowerVM VIOS 4.1.\nNetwork exposure is present if the affected services are accessible via the network interface, potentially permitting remote attackers to initiate the attack without local shell access.\nAuthentication requirements and privilege requirements depend on the specific exposed service handling the unvalidated input, though the flaw facilitates remote disruption.\nThe payload behavior centers on crashing the target service or system kernel via memory corruption or exception triggering rather than arbitrary code execution, resulting directly in a denial of service condition."
}