FreeBSDOperating system
CVE-1999-0323
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 · uneditedFreeBSD mmap function allows users to modify append-only or immutable files.
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 confidenceThis vulnerability in FreeBSD's mmap() system call allows unprivileged users to bypass file permission restrictions and modify files marked as append-only or immutable, which should not be possible under normal security models.
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
= 2.2= 3.0= 2.0.4= 2.2CVSS 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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Identify the exact operating system and versionRun 'uname -a' on BSD systems or check the system documentation to determine the precise version numberAffected if The system is running FreeBSD 2.2, Bsdi Bsd Os 3.0, Netbsd 2.0.4, or OpenBSD 2.2 exactly as listed in the affected versions
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Confirm the kernel release versionRun 'uname -v' or 'sysctl kern.version' to obtain the kernel build detailsAffected if The kernel version matches one of the specific affected releases listed for this CVE
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Check for unprivileged user accountsReview /etc/passwd or run 'id' command to identify if non-root users exist on the systemAffected if Unprivileged users exist on the system, which is a prerequisite for this vulnerability to be exploitable
The environment is affected if the installed OS version exactly matches FreeBSD 2.2, Bsdi Bsd Os 3.0, Netbsd 2.0.4, or OpenBSD 2.2, as these are the only versions listed as vulnerable to CVE-1999-0323.
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.
dbcve · scopedApply available FreeBSD security patches for this vulnerability and review file system permission configurations to limit exposure until patches can be applied.
Modern supported versions: FreeBSD 13.x/14.x, OpenBSD 7.x, NetBSD 9.x/10.x
- 1. Identify the affected system (FreeBSD 2.2, BSD/OS 3.0, NetBSD 2.0.4, or OpenBSD 2.2)
- 2. Due to the extreme age of these versions (late 1990s), no vendor patches are available for these specific releases
- 3. Upgrade to a modern, supported version of the respective operating system:
- - For FreeBSD: Upgrade to FreeBSD 13.x or 14.x (current stable releases)
- - For OpenBSD: Upgrade to OpenBSD 7.x (current release)
- - For NetBSD: Upgrade to NetBSD 9.x or 10.x (current releases)
- 4. For BSD/OS: This was a commercial product (BSDI) that is no longer supported; migrate to FreeBSD or another BSD derivative
- 5. After upgrade, verify the mmap() function properly enforces append-only and immutable file flags
Generated from the published advisory — verify against the referenced sources before acting.
Fix this in FreeBSD
Scoped from the published advisory
- Consultation4.0 h
- Implementation8.0 h
- Testing12.0 h
- Review / QA6.0 h
An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $8,192.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-1999-0323 — 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-1999-0323 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
- No spam, self-promotion, credentials, or personal data