FreeBSDOperating system
CVE-2023-5369
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 · uneditedBefore correction, the copy_file_range system call checked only for the CAP_READ and CAP_WRITE capabilities on the input and output file descriptors, respectively. Using an offset is logically equivalent to seeking, and the system call must additionally require the CAP_SEEK capability. This incorrect privilege check enabled sandboxed processes with only read or write but no seek capability on a file descriptor to read data from or write data to an arbitrary location within the file corresponding to that file descriptor.
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 · high confidenceThe copy_file_range system call incorrectly validated only CAP_READ and CAP_WRITE capabilities on input and output file descriptors, failing to require CAP_SEEK for offset operations. This allowed sandboxed processes with only read or write permissions to read from or write to arbitrary file positions by specifying offsets, bypassing the intended seek capability requirement.
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
= 13.2CVSS 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
- Privileges
- Low
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- High
- Integrity
- High
- Availability
- None
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N
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.
-
Identify the FreeBSD versionRun 'uname -r' or check /etc/os-release to determine the installed FreeBSD versionAffected if The version is exactly 13.2 (FreeBSD 13.2)
-
Determine if Capsicum capability sandboxing is in useReview running processes and sandbox configurations for programs that employ CAP_READ and CAP_WRITE capabilities without CAP_SEEK. Check for processes using libcapsicum or capsicum-helper utilitiesAffected if Sandboxed applications using capability-based file access controls with copy_file_range are present
-
Audit copy_file_range usage in sandboxed contextsReview application source code or trace system calls using 'dtrace' or 'ktrace' to identify if copy_file_range is invoked with file descriptors that lack CAP_SEEK capability but have CAP_READ or CAP_WRITEAffected if Applications call copy_file_range with descriptors lacking CAP_SEEK while having CAP_READ or CAP_WRITE permissions
-
Check for privilege escalation indicatorsExamine system and application logs for unexpected file access patterns, particularly attempts to read from or write to arbitrary file offsets in sandboxed contextsAffected if Logs show copy_file_range operations accessing file positions outside expected ranges in capability-constrained environments
A system is affected if it runs FreeBSD 13.2 and uses Capsicum-based sandboxing where copy_file_range is invoked with CAP_READ or CAP_WRITE without CAP_SEEK validation.
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 dataApply the kernel patch that adds CAP_SEEK capability validation to copy_file_range. If immediate patching is unavailable, review and restrict sandbox configurations that rely on capability-based file access controls to limit exposure to this privilege bypass.
Fix this in FreeBSD
Scoped from the published advisory
- Consultation4.0 h
- Implementation8.0 h
- Testing16.0 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 $9,152.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2023-5369 — 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-2023-5369 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
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.
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