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 NULL pointer dereference.

Executive Summary

Technical Details

Mitigations

References

Additional Metadata

{
  "score": "7.5",
  "pubDate": "2026-08-19T15:16:57.687Z",
  "pubdate": "2026-08-19T15:16:57.687Z",
  "executiveSummary": "This vulnerability involves a NULL pointer dereference flaw affecting IBM AIX 7.2, 7.3, and IBM PowerVM VIOS 4.1. The flaw allows an unauthenticated remote attacker to trigger a denial of service condition on target systems. The root vulnerability arises from improper handling of specific system requests or inputs, leading to an application or kernel crash when the software attempts to dereference an uninitialized or null memory address. Successful exploitation directly impacts system availability, potentially causing system instability, service interruption, or kernel panics requiring administrative intervention. The attack vector is network-based, granting remote threat actors the capability to disrupt critical infrastructure without requiring prior authentication or privileged access. Given the widespread deployment of IBM AIX and PowerVM VIOS in enterprise environments, disruption of these systems poses severe operational risks. Remediation requires applying official vendor patches and updates as soon as they become available from IBM product support.",
  "technicalDetails": "The vulnerability is classified as a NULL pointer dereference issue residing within core components of IBM AIX 7.2, 7.3, and IBM PowerVM VIOS 4.1. A NULL pointer dereference occurs when an application or kernel module attempts to read or write memory using a pointer that does not point to a valid memory address, typically initialized to zero due to error handling failures, race conditions, or unvalidated input parameters.\nIn the context of the affected operating systems and hypervisor platforms, exploitation occurs when a remote attacker sends specially crafted network packets or malformed protocol requests to a vulnerable service running on the target. Upon receiving the input, the internal parsing logic or underlying network stack fails to correctly validate the operational state or data structure integrity. Consequently, a pointer variable meant to reference a valid control block or memory buffer remains NULL.\nWhen the execution flow subsequently attempts to access members or invoke methods via this invalid pointer, the processor encounters an invalid memory access violation. This triggers an immediate exception handling routine within the kernel or daemon process. Because the exception cannot be safely handled or recovered from at the software level, it results in an immediate crash of the affected daemon or a complete kernel panic of the host operating system or VIOS partition.\nThe attack vector is fully remote, requiring network connectivity to the target system's exposed services. The vulnerability can be exploited by an unauthenticated attacker over the network, meaning no prior credentials, user interaction, or elevated privileges are necessary to initiate the attack sequence. The primary post-exploitation impact is limited to denial of service, as repeated triggering of the condition forces continuous reboots or sustained downtime, severely impacting business continuity and system availability."
}