Description

IBM AIX 7.2, and 7.3 and IBM PowerVM VIOS 4.1 could allow a remote attacker to access NFS-exported filesystems due to improper authentication.

Executive Summary

Technical Details

Mitigations

References

Additional Metadata

{
  "score": "8.2",
  "pubDate": "2026-08-19T15:16:56.727Z",
  "pubdate": "2026-08-19T15:16:56.727Z",
  "executiveSummary": "This vulnerability involves an improper authentication flaw affecting the Network File System (NFS) implementation within IBM AIX and IBM PowerVM VIOS. The weakness allows a remote attacker to bypass intended authentication mechanisms and gain unauthorized access to NFS-exported filesystems. The impact of successful exploitation includes the potential exposure, retrieval, or modification of sensitive data residing on the shared storage volumes. Affected products include IBM AIX 7.2, IBM AIX 7.3, and IBM PowerVM VIOS 4.1. The risk implications are severe, as unauthorized data access compromises confidentiality and integrity principles within enterprise environments utilizing these operating systems. The capability required by an attacker is remote network access, enabling them to interact directly with the vulnerable NFS services without valid credentials. Exploitation conditions rely on the presence of improperly secured or misauthenticated NFS exports on the target hosts, permitting unauthorized clients to mount and traverse restricted filesystems.",
  "technicalDetails": "The vulnerability resides within the NFS daemon and authentication handling components of IBM AIX 7.2, IBM AIX 7.3, and IBM PowerVM VIOS 4.1. The root cause stems from improper authentication logic, where the system fails to adequately verify the identity of connecting clients or enforce strict access control lists (ACLs) during the NFS mount and file request operations. Network exposure is direct, as the NFS service typically listens on standard network ports accessible to remote systems across the network boundary. No prior authentication or privileged access is inherently required by the attacker to initiate the attack sequence, provided the target exposes the vulnerable NFS service and possesses misconfigured or loosely restricted export configurations. The exploitation method involves crafting specialized network requests directed at the NFS server, designed to bypass the cryptographic or credential-based handshake typically required to establish a valid session. During the attack flow, the remote attacker sends malicious RPC (Remote Procedure Call) commands or mount requests that exploit the flawed authentication validation routine. Because the affected component improperly validates the source or credentials of the incoming request, the server erroneously grants session establishment and returns file handle references to the unauthorized client. Once the file handles are acquired, the attacker can leverage standard NFS protocol operations to read, write, or traverse the directory structures of the exported filesystems as if they were an authenticated and authorized user. The post-exploitation impact includes unauthorized data exfiltration of sensitive configuration files, system data, or enterprise workloads hosted on the shared storage, as well as potential data tampering depending on the export permissions granted by the flawed daemon logic."
}