Description

IBM AIX 7.2, and 7.3 and IBM PowerVM VIOS 4.1 could allow a local attacker to execute arbitrary code due to an out-of-bounds write.

Executive Summary

Technical Details

Mitigations

References

Additional Metadata

{
  "score": "6.7",
  "pubDate": "2026-08-19T20:17:11.333Z",
  "pubdate": "2026-08-19T20:17:11.333Z",
  "executiveSummary": "An out-of-bounds write vulnerability has been identified in IBM AIX 7.2, 7.3, and IBM PowerVM VIOS 4.1. This security flaw originates from improper bounds checking within memory management operations, potentially allowing a local attacker to execute arbitrary code with elevated privileges. The vulnerability poses significant risk implications for enterprise environments utilizing these operating systems and virtualization platforms, as successful exploitation compromises the integrity, availability, and confidentiality of the affected host and associated logical partitions. The attacker capabilities require local system access to the targeted machine to deliver and execute malicious payloads capable of triggering the out-of-bounds memory corruption. Due to the nature of the vulnerability, execution of arbitrary code within the kernel or privileged system context can lead to complete system compromise, bypassing standard security controls. Organizations running the specified versions must prioritize remediation efforts by applying vendor-supplied updates or patches as soon as they become available to neutralize the local attack vector and prevent unauthorized code execution.",
  "technicalDetails": "The vulnerability is classified as an out-of-bounds write resulting from a failure to adequately validate input lengths or memory boundaries prior to executing write operations within the vulnerable component of IBM AIX 7.2, 7.3, and IBM PowerVM VIOS 4.1. The root cause lies in memory management logic where data is written past the allocated buffer boundaries, leading to heap or stack corruption depending on the specific execution context. Exploitation of this flaw requires a local attacker to have authenticated access to the target system with sufficient capability to interface with the vulnerable subsystem, driver, or system call handler. While network exposure is not a direct vector for this vulnerability, local privilege escalation or arbitrary code execution paths can be leveraged if the attacker has lower-privileged shell access. The attack flow begins with the local user crafting a malicious input, system call, or interaction that supplies data exceeding the expected size constraints of the internal buffer. When the vulnerable function processes this input, the lack of boundary enforcement causes the write operation to overflow the destination buffer, overwriting adjacent memory structures, function pointers, or control data. By carefully manipulating the memory layout prior to triggering the out-of-bounds write, the attacker can hijack the control flow of the execution thread, redirecting it to malicious shellcode or payload routines. The payload behavior under successful exploitation includes the execution of arbitrary code within the context of the affected process or kernel space, enabling the local attacker to achieve privilege escalation, install persistent backdoors, or compromise underlying virtual machines managed by IBM PowerVM VIOS. Post-exploitation impact encompasses full administrative control over the local operating system instance, potential escape scenarios depending on the virtualization boundary interactions, and severe degradation of system reliability and data security."
}