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 out-of-bounds read.

Executive Summary

Technical Details

Mitigations

References

Additional Metadata

{
  "score": "4.8",
  "pubDate": "2026-08-19T20:17:07.967Z",
  "pubdate": "2026-08-19T20:17:07.967Z",
  "executiveSummary": "A denial of service vulnerability exists in IBM AIX 7.2, 7.3, and IBM PowerVM VIOS 4.1. The vulnerability is classified as an out-of-bounds read flaw affecting the core operating system components.\nSuccessful exploitation of this security defect allows a remote attacker to trigger a crash or system instability, resulting in a denial of service condition for the affected hypervisor or operating system environment.\nThe risk implication is severe for availability, as critical enterprise infrastructure running IBM PowerVM VIOS or AIX can be rendered unresponsive without requiring localized physical access.\nAttacker capabilities involve remote network interaction to transmit maliciously crafted inputs that trigger the bounds-checking failure during memory processing.\nNo specific authentication or specialized privilege requirements are explicitly detailed beyond remote network reachability to the vulnerable service, though specific protocol vectors depend on the underlying subsystem handling the out-of-bounds memory read.",
  "technicalDetails": "The vulnerability stems from a bounds-checking validation failure within memory management or packet/data parsing routines handling inputs on IBM AIX 7.2, 7.3, and IBM PowerVM VIOS 4.1.\nSpecifically, an out-of-bounds read occurs when the affected component attempts to read memory locations past the allocated buffer boundary. This typically happens due to insufficient validation of length fields or index parameters supplied via network or inter-process communication interfaces.\nThe attack flow begins when a remote attacker constructs a malformed payload designed to manipulate internal size or offset indicators within the target protocol or data structure. Upon transmission to the vulnerable endpoint, the parsing routine processes the input without properly verifying whether the read offset exceeds the permissible memory boundaries allocated for the buffer.\nWhen the vulnerable function executes the read operation beyond the legitimate buffer limits, it attempts to access restricted or unmapped memory regions.\nThis invalid memory access triggers a segmentation fault, kernel panic, or exception handling failure, depending on whether the execution context is user-space or kernel-space. Consequently, the operating system kernel or the affected daemon crashes, producing a denial of service state.\nThe vulnerable components reside within the core networking or system service stacks of IBM AIX versions 7.2 and 7.3, as well as IBM PowerVM VIOS version 4.1.\nExploitation does not inherently provide remote code execution or arbitrary read capabilities beyond the immediate crash condition, as the fundamental nature of the defect is an out-of-bounds read resulting in a termination of service rather than memory disclosure or write primitives.\nNetwork exposure is required for remote attackers to deliver the malformed input sequence, targeting exposed services running on the affected AIX or VIOS instances."
}