FreeBSDOperating system
CVE-1999-0304
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 · uneditedmmap function in BSD allows local attackers in the kmem group to modify memory through devices.
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 confidenceThe mmap() function in older BSD systems contained a vulnerability allowing members of the 'kmem' group to map device memory directly, enabling modification of kernel memory through device files. This was a local privilege escalation issue where the mmap implementation failed to properly restrict memory mapping permissions for privileged group users.
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
- Local
- Complexity
- Low
- Authentication
- None
- Confidentiality
- Complete
- Integrity
- Complete
- Availability
- Complete
AV:L/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 BSD variant and exact versionRun 'uname -a' or 'cat /etc/motd' to determine the exact OS version and variantAffected if The system is FreeBSD 2.2, Bsdi Bsd Os 3.0, Netbsd 2.0.4, or OpenBSD 2.2 exactly
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Verify if the 'kmem' group exists on the systemCheck /etc/group for a 'kmem' entry using 'grep kmem /etc/group'Affected if A 'kmem' group is defined in /etc/group
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Identify users who are members of the 'kmem' groupRun 'grep kmem /etc/group' to list all users in the kmem groupAffected if Any non-root user account is listed as a member of the kmem group
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Confirm mmap access to device memory filesCheck if /dev/mem and /dev/kmem exist and have permissions allowing the kmem group to read/write (ls -la /dev/mem /dev/kmem)Affected if /dev/mem or /dev/kmem are readable/writable by the kmem group or all users
A user is affected if they are running one of the exact listed BSD versions (2.2, 3.0, 2.0.4) and have the kmem group with non-root members, allowing potential local privilege escalation via mmap device memory mapping.
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 dataOrganizations should verify they are not running legacy BSD systems from this era (1990s). If legacy systems exist, apply historical patches from BSD vendors or migrate to supported system versions. Modern BSD and Unix-like systems have long addressed this vulnerability through improved mmap access controls.
Fix this in FreeBSD
Scoped from the published advisory
- Consultation2.0 h
- Implementation1.0 h
- Testing2.0 h
- Review / QA1.0 h
An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $1,696.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-1999-0304 — 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-1999-0304 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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- Verified mitigations, workarounds, and config changes
- Version or environment caveats, and links to real fixes
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