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CVE Record

CVE-1999-0554: NFS exports system-critical data to the world, e.g.

NFS exports system-critical data to the world, e.g. / or a password file.

UnknownCVSS not scoredNot KEV-listedUpdated
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Glexia's TakeAutomated analysishigh

Security readout for executives and security teams

Plain-English summary

This legacy advisory describes a misconfiguration where a Unix NFS (Network File System) server shares sensitive parts of its file system, such as the root directory or password file, with any host on the network. In plain terms, a server intended to share limited files is instead handing out system-critical data to the world, allowing outsiders to read or alter files they should never see.

Executive priority

Low urgency for modern cloud estates, but treat as a housekeeping priority wherever legacy Unix, storage appliances, or lab systems still run NFS. A single misconfigured export can expose credentials and system files across an internal network, so include NFS exports in routine configuration audits.

Technical view

CVE-1999-0554 documents an insecure NFS export configuration: the exports file grants unrestricted access (no host list, no root_squash, no read-only flag) to sensitive paths like / or /etc/passwd. Any client that can reach the NFS ports (portmapper 111, mountd, nfsd 2049) can mount those shares and read or modify system files, enabling credential harvesting and potential privilege escalation.

Likely exposure

Exposure is limited to environments still running NFS servers with permissive /etc/exports entries, typically legacy Unix or Linux hosts. Modern networks that firewall NFS ports or use Kerberos-authenticated NFSv4 are largely unaffected, but forgotten lab, storage, or appliance systems reachable on flat internal networks remain at real risk.

Exploitation context

No CISA KEV entry and no public exploit campaign is cited in the source bundle. The issue is a well-known misconfiguration class that has been trivially abusable since the 1990s using standard NFS client tools; active exploitation in a given environment depends entirely on whether such exports are reachable from an attacker's network position.

Researcher notes

The record is a historical, product-agnostic configuration weakness rather than a code vulnerability; there is no CVSS, CWE, or affected-product list in the bundle. Treat it as guidance to sweep for permissive NFS exports and pair it with CWE-732 (incorrect permission assignment) style checks. Any assertion about active exploitation requires environment-specific evidence, not this record.

Mitigation direction

  • Review /etc/exports and remove world-readable or root-writable entries pointing at / or password files.
  • Restrict exports to specific host lists and apply root_squash plus read-only where possible.
  • Block NFS ports (111, 2049, mountd) at network and host firewalls from untrusted segments.
  • Migrate to NFSv4 with Kerberos (sec=krb5p) authentication where feasible.
  • Follow current vendor Unix/Linux NFS hardening guidance for the specific distribution in use.

Validation and detection

  • Run showmount -e against each NFS server and confirm no share exposes / or sensitive system paths.
  • Audit /etc/exports on all NFS hosts for wildcard clients or missing root_squash and ro flags.
  • Scan internal ranges for open TCP/UDP 2049 and 111 and flag any unexpected NFS listeners.
  • Confirm firewall rules block NFS access from user, guest, and internet-facing segments.
  • Verify monitoring alerts on new NFS mounts of sensitive paths.
Prepared
Confidence
medium
Sources
3

Public sources used

Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.

Potential ATT&CK relevance

Conservative CVE-to-ATT&CK context

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ATT&CK lookup starting points

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Credential and access behavior lookup

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CVE-1999-0554 mapping review

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Vulnerability profileCVE Program record
Severity
Unknown
CVSS
Not scored
Known Exploited
No
Published
Official CVE source material

CNA and ADP enrichment extracted from CVE v5

These fields come from the CVE record and ADP containers, not from Glexia's Take. They preserve time-varying source decisions such as CISA SSVC, KEV status, CVSS metrics, and provider references.

0CVSS vectors
0Timeline events
0ADP providers
2Source links

CVSS and timeline data

No CVSS vectors or timeline events were available in the normalized CVE source material.

Source materials

Affected products

Products and packages named in the record

VendorProductVersion / packageStatus
n/an/an/aListed
Weakness

CWE details

No CWE listed

CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.