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FreeBSDOperating system

CVE-1999-0085

HIGH · 7.5 CVSS v2.0 Published 1996-08-21
Mitigation only
No fix yet — a mitigation exists. There is no fixed release. A documented workaround reduces exposure in the meantime.
See remediation →
84/100
Remediation priority · High
Remotely reachable No privileges Zero-click

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 · unedited
Buffer overflow in rwhod on AIX and other operating systems allows remote attackers to execute arbitrary code via a UDP packet with a long hostname.

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 confidence

A remote buffer overflow vulnerability in the rwhod daemon allows attackers to execute arbitrary code by sending a UDP packet with an overly long hostname field. The rwhod service, which operates on UDP port 513, does not properly validate input length before copying it into a fixed-size buffer.

MitigationDisable or remove the rwhod service if not required, as it is obsolete and rarely needed on modern systems. If rwhod is required, block UDP port 513 at the network perimeter or apply vendor-supplied patches for affected AIX and other OS versions.

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 data
FreeBSDOperating system
Affected:= 6.2
AixOperating system
Affected:= 4.2
NetbsdOperating system
Affected:= 2.0.4

CVSS 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
Partial
Integrity
Partial
Availability
Partial

AV:N/AC:L/Au:N/C:P/I:P/A:P

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 checks

Work through these to decide whether this CVE applies to you.

  1. Verify if rwhod daemon is running
    Check for processes named 'rwhod' or for UDP port 513 in a listening state using commands like 'netstat -anu' or 'ss -unu' to see if port 513 is open
    Affected if rwhod is actively running and listening on UDP port 513
  2. Confirm your FreeBSD version
    Run 'uname -a' or check /etc/os-release (FreeBSD 8+), or 'sysctl kern.osreldate' for older versions
    Affected if Running FreeBSD version 6.2 specifically
  3. Confirm your IBM AIX version
    Run 'oslevel -r' or 'bootinfo -r' to determine the AIX version installed
    Affected if Running AIX version 4.2 specifically
  4. Confirm your NetBSD version
    Run 'uname -a' or check /etc/release to identify the NetBSD version
    Affected if Running NetBSD version 2.0.4 specifically
  5. Verify rwhod binary presence
    Check for the existence of the rwhod binary in standard locations such as /usr/sbin/rwhod using 'ls -la /usr/sbin/rwhod' or similar path inspection
    Affected if The rwhod binary exists on the system and the service is enabled to start

You are affected only if rwhod is running on UDP port 513 AND your OS version matches FreeBSD 6.2, AIX 4.2, or NetBSD 2.0.4.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

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 data
Mitigation available No clean upgrade yet — mitigate in the meantime
Mitigation

Disable or remove the rwhod service if not required, as it is obsolete and rarely needed on modern systems. If rwhod is required, block UDP port 513 at the network perimeter or apply vendor-supplied patches for affected AIX and other OS versions.

Fix this in FreeBSD Scoped from the published advisory
  • Consultation2.0 h
  • Implementation2.0 h
  • Testing1.0 h
  • Review / QA1.0 h
6.0 hours of engineering $1,090
Get help mitigating

An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $1,744.

Scan for this in your stack

Free · runs locally
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References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-1999-0085 in production — separate from our analysis above.

No notes yet

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What this is

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.

What belongs here
  • Verified mitigations, workarounds, and config changes
  • Version or environment caveats, and links to real fixes
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