Description

IBM AIX 7.2, and 7.3 and IBM PowerVM VIOS 4.1 could allow a local attacker to gain elevated privileges due to improper resolution of symbolic links.

Executive Summary

Technical Details

Mitigations

References

Additional Metadata

{
  "score": "7.1",
  "pubDate": "2026-08-20T22:17:10.147Z",
  "pubdate": "2026-08-20T22:17:10.147Z",
  "executiveSummary": "A privilege escalation vulnerability exists in IBM AIX 7.2 and 7.3, as well as IBM PowerVM VIOS 4.1, stemming from the improper resolution of symbolic links.\nThis security flaw enables a locally authenticated attacker with low-privileged access to manipulate symbolic links, resulting in unauthorized elevation of privileges on the affected operating system and virtualization environments.\nThe risk implications are severe, as successful exploitation allows local users to bypass standard access control enforcement mechanisms, potentially leading to root-level compromise of the host or virtual I/O server.\nThe attack vector requires local access and user interaction or execution capabilities within the operating system environment, but does not necessitate complex network exposure or prior administrative privileges.\nOrganizations deploying the affected IBM AIX and PowerVM VIOS versions face potential system integrity and confidentiality compromises if local threat actors successfully weaponize this symbolic link handling defect.",
  "technicalDetails": "The root cause of the vulnerability lies within the insecure handling and improper resolution of symbolic links by administrative scripts, binaries, or system daemons operating within IBM AIX 7.2, 7.3, and IBM PowerVM VIOS 4.1.\nWhen privileged operations interact with file system paths without adequately validating or sanitizing symbolic links, a race condition or time-of-check to time-of-use (TOCTOU) vulnerability can be introduced.\nAn authenticated local attacker leverages this flaw by creating maliciously crafted symbolic links pointing to sensitive system files, configuration files, or binaries that are routinely accessed or modified with elevated privileges.\nDuring the attack flow, the vulnerable component processes the file path while following the attacker-controlled symbolic link, causing privileged routines to read, write, or execute operations against unintended system files.\nThis improper resolution allows the local user to overwrite critical system binaries, manipulate permission boundaries, or inject malicious payloads into privileged execution contexts.\nThe authentication requirement is local access with standard user privileges, and exploitation does not require network exposure or protocol interaction, as the attack vectors are restricted to the local file system and execution environment.\nThe post-exploitation impact includes complete privilege escalation to root or superuser status, granting the attacker unrestricted control over the affected IBM AIX or IBM PowerVM VIOS instance, enabling persistent access, data exfiltration, or further lateral movement across the virtualized infrastructure."
}