# CVE-1999-0169: NFS unauthorized file access via UID spoofing

Source: https://junglewise.ai/threats/cve-1999-0169-nfs-unauthorized-file-access-via-uid-spoofing  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 1997-07-01. Updated: 2026-05-10  
License: CC BY 4.0 with a link back

CVE-1999-0169 · Severity: critical · CVSS 10 · Published 1997-07-01

A critical vulnerability exists in the Network File System (NFS) protocol that allows unauthorized users to bypass security controls. By providing a false user identity, an attacker can gain full access to read or modify any file on the affected server. This could lead to the complete theft of sensitive data, destruction of files, or total system compromise.

Technologies: [Sun Nfs](https://junglewise.ai/threats/technologies/nfs). Vendors: [Sun](https://junglewise.ai/threats/vendors/sun).

## Quick answers

**Is CVE-1999-0169 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-1999-0169 being exploited in the wild.

**How severe is CVE-1999-0169?** Critical severity, with a CVSS score of 10, published 1 July 1997.

**Which products and versions are affected?** Generic NFS.

**Is there a fix for CVE-1999-0169?** No fixed version is recorded yet. Check the vendor's advisory in the references below. If you run it, Junglewise drafts a mitigation that fits your setup and applies it once you approve, with senior security engineers behind it.

**How is CVE-1999-0169 attacked?** It is attacked over the network, in a hosted service.

**Am I affected by CVE-1999-0169?** Check whether you run Sun Nfs. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## Technical details

The Network File System (NFS) protocol contains a fundamental flaw in how it handles user authentication and authorization. An attacker can craft network requests using a spoofed User Identifier (UID) to impersonate any user, including the root user. Because the service relies on the client-provided UID without sufficient server-side verification, the attacker gains full read and write permissions to all files exported by the NFS server. This is a network-based attack that requires no prior authentication, leading to a complete compromise of confidentiality, integrity, and availability.

## Affected products

- Generic NFS

## Timeline

- 1997-07-01: disclosed: Initial publication date in NVD

## References

- [https://exchange.xforce.ibmcloud.com/vulnerabilities/CVE-1999-0169](https://exchange.xforce.ibmcloud.com/vulnerabilities/CVE-1999-0169)

## Related threats

- [NFS directory traversal via parent directory navigation](https://junglewise.ai/threats/cve-1999-0166-nfs-directory-traversal-via-parent-directory-navigation)
- [Generic NFS Server privilege escalation via mknod kmem device](https://junglewise.ai/threats/cve-1999-0084-generic-nfs-server-privilege-escalation-via-mknod-kmem-device)