CVE-1999-0169
Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.
NVD · uneditedNFS allows attackers to read and write any file on the system by specifying a false UID.
Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.
dbcve analysis · moderate confidenceNFS (Network File System) version 2/3 trusts client-supplied User Identifiers (UIDs) for file access control without server-side verification. An attacker can spoof their UID to match any user (including root) and gain unauthorized read/write access to files on exported filesystems.
Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.
Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.
NVD · CPE dataall versionsCVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.
From the vector- Attack vector
- Network
- Complexity
- Low
- Authentication
- None
- Confidentiality
- Complete
- Integrity
- Complete
- Availability
- Complete
AV:N/AC:L/Au:N/C:C/I:C/A:C
Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.
dbcve checksWork through these to decide whether this CVE applies to you.
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Determine if NFS service is runningRun 'showmount -e localhost' or check for nfsd processes with 'ps aux | grep nfs'Affected if NFS daemon is actively running and exporting filesystems
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Identify exported filesystemsInspect /etc/exports on Unix/Linux systems, or the NFS export configuration for your systemAffected if Filesystems are exported to the network without restrictions
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Check NFS version supportReview /etc/exports or NFS server configuration for version settings. Look for explicit v2 or v3 settings, or check mountd/nfsd daemon versionsAffected if NFSv2 or NFSv3 protocols are enabled (these versions trust client-supplied UIDs)
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Verify export options applied to shared filesystemsRun 'showmount -e <server>' or inspect /etc/exports entries for each exported path. Look for 'root_squash' or 'all_squash' keywordsAffected if Exported filesystems lack 'root_squash' or 'all_squash' options - the server maps root to anonymous and does not validate UIDs
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Determine NFS server network exposureCheck if NFS ports (2049/tcp, 2049/udp, plus mountd ports) are accessible from untrusted networks using 'netstat -an | grep 2049' or firewall rules reviewAffected if NFS server is reachable from untrusted or external networks
Your environment is affected if NFSv2 or NFSv3 is running, filesystems are exported without root_squash/all_squash, and the server is accessible from untrusted networks - allowing UID spoofing attacks.
Generated from the published advisory. Verify against your own configuration.
Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.
From vendor dataRestrict NFS access to trusted networks via firewall rules, disable NFSv2/v3 in favor of NFSv4 which uses Kerberos authentication, or implement mount restrictions using 'root_squash' and 'all_squash' options to map root to anonymous.
- Consultation4.0 h
- Implementation8.0 h
- Testing4.0 h
- Review / QA2.0 h
An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $5,120.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-1999-0169 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.
References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.
Primary sourcesPractitioner notes
ContributedPeer-ranked notes from engineers who’ve handled CVE-1999-0169 in production — separate from our analysis above.
The advisory tells you what broke. It rarely tells you what actually worked. If you’ve dealt with this one, that detail is what the next engineer is searching for.
- The version that genuinely resolved it — not the one the vendor claimed
- A config change or rule that shut the vector down
- A gotcha in the upgrade path that cost you an afternoon
No notes yet
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A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.
- Verified mitigations, workarounds, and config changes
- Version or environment caveats, and links to real fixes
- No weaponised exploit code, or anything meant to cause harm
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