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 write.

Executive Summary

Technical Details

Mitigations

References

Additional Metadata

{
  "score": "7.5",
  "pubDate": "2026-08-19T15:16:57.207Z",
  "pubdate": "2026-08-19T15:16:57.207Z",
  "executiveSummary": "This vulnerability involves an out-of-bounds write flaw affecting IBM AIX 7.2, IBM AIX 7.3, and IBM PowerVM VIOS 4.1. The security defect poses a significant availability risk to enterprise infrastructure by potentially allowing a remote attacker to trigger a denial of service condition. An out-of-bounds write typically occurs when software writes data past the end, or before the beginning, of the intended buffer, leading to memory corruption, application crashes, or system instability. The primary impact of successful exploitation is targeted disruption of service, compromising system uptime and operational integrity for critical virtualization and operating system environments. Remote attackers leverage network-accessible vectors to interact with vulnerable components without necessarily requiring complex authentication or elevated privileges, depending on the specific network exposure of the targeted service. Risk implications center around unexpected system panics, service outages, and the potential need for manual intervention or reboots to restore affected instances. As the advisory highlights remote exploitability resulting in a denial of service, administrators must prioritize identifying exposed services and applying vendor-supplied fixes or configuration workarounds to mitigate potential attack vectors targeting memory management and input validation routines within the affected operating systems and virtualization management components.",
  "technicalDetails": "The vulnerability is characterized as an out-of-bounds write defect residing within core components of IBM AIX 7.2, IBM AIX 7.3, and IBM PowerVM VIOS 4.1. An out-of-bounds write vulnerability fundamentally stems from insufficient boundary checks and inadequate input validation when handling dynamically sized data structures, memory buffers, or network payloads. During execution, the vulnerable component calculates memory offset destinations without adequately verifying that the target address resides strictly within allocated buffer boundaries. Consequently, an attacker crafting a specialized remote input sequence can force the routine to write malicious or malformed data to adjacent memory regions.\nThe attack flow begins with a remote threat actor interacting with a network-exposed service running on the targeted IBM AIX or PowerVM VIOS instance. The attacker transmits a crafted payload designed to manipulate internal state variables or buffer length indicators processed by the vulnerable function. Upon receiving the malformed input, the application or kernel subsystem executes memory write operations based on the corrupted or unvalidated offsets. Because bounds checking is bypassed or improperly implemented, the execution context overwrites critical control data, adjacent heap or stack variables, or kernel memory structures.\nThe resulting memory corruption disrupts normal program execution flow or corrupts critical system data structures, immediately precipitating a system panic, kernel fault, or application crash, thereby manifesting as a denial of service. The affected versions include IBM AIX 7.2, IBM AIX 7.3, and IBM PowerVM VIOS 4.1. Network exposure is a key vector facilitating remote exploitation capabilities. Depending on the specific daemon or interface handling the unvalidated input, exploitation may not require prior authentication or elevated privileges, allowing unauthenticated remote actors to degrade system availability directly. Post-exploitation impact is principally focused on availability disruption rather than arbitrary code execution, though unhandled memory corruption conditions in core operating system layers invariably lead to complete node failure requiring administrative reboot procedures."
}