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FreeBSDOperating system

CVE-1999-0052

HIGH · 7.5 CVSS v3.1 Published 1998-11-04
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
IP fragmentation denial of service in FreeBSD allows a remote attacker to cause a crash.

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

IP fragmentation handling vulnerability in FreeBSD allows remote attackers to send specially crafted IP fragments that cause the system to crash, resulting in denial of service.

MitigationUpdate FreeBSD to a patched version or apply available kernel patches for IP fragmentation handling; consider network-based filtering of fragmented packets as a compensating control.

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:= 1.1.5.1= 2.0= 2.0.5= 2.1.0= 2.1.5= 2.1.6= 2.1.7.1= 2.2.2= 2.2.8
Bsd OsOperating system
Affected:= 4.0
OpenBSDOperating system
Affected:= 2.2= 2.3= 2.4

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
Privileges
None
User interaction
None
Scope
Unchanged
Confidentiality
None
Integrity
None
Availability
High

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

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. Identify the running operating system
    Run 'uname -a' or check /etc/os-release (if available) to determine the OS name and version
    Affected if The system is running FreeBSD, BSDi BSD/OS, or OpenBSD matching the vulnerable versions listed
  2. Confirm FreeBSD version
    Run 'sysctl kern.version' or check 'cat /etc/motd' to display the installed FreeBSD version
    Affected if The version matches FreeBSD 1.1.5.1, 2.0, 2.0.5, 2.1.0, 2.1.5, 2.1.6, 2.1.7.1, 2.2.2, or 2.2.8
  3. Confirm OpenBSD version
    Run 'uname -r' or check the banner at login to display the installed OpenBSD version
    Affected if The version matches OpenBSD 2.2, 2.3, or 2.4
  4. Confirm BSDi BSD/OS version
    Check the system with 'uname -a' or examine /var/run/dmesg.boot for the BSDi version banner
    Affected if The version matches BSDi BSD/OS 4.0
  5. Verify IP fragmentation handling is active
    Check if IP forwarding or packet forwarding is enabled: run 'sysctl net.inet.ip.forwarding' on FreeBSD or check the kernel configuration file for IPFRAG options
    Affected if The system has IP forwarding enabled and is processing network traffic, exposing the fragmentation handling code to remote attackers

The system is affected if it is running any of the specific FreeBSD, BSDi BSD/OS, or OpenBSD versions listed AND is processing network traffic that includes IP fragments.

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

Update FreeBSD to a patched version or apply available kernel patches for IP fragmentation handling; consider network-based filtering of fragmented packets as a compensating control.

Fix this in FreeBSD Scoped from the published advisory
  • Consultation2.0 h
  • Implementation4.0 h
  • Testing3.0 h
  • Review / QA2.0 h
11.0 hours of engineering $1,930
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An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $3,088.

Scan for this in your stack

Free · runs locally
dbcve dependency scanner

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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-1999-0052 in production — separate from our analysis above.

No notes yet

Be the first to add a field note for this CVE — a mitigation you’ve verified, a version caveat, or a link to a working fix. Sign in above to contribute.

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
  • No weaponised exploit code, or anything meant to cause harm
  • No spam, self-promotion, credentials, or personal data