Debian LinuxOperating system · Debian
CVE-2023-0386
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 · uneditedA flaw was found in the Linux kernel, where unauthorized access to the execution of the setuid file with capabilities was found in the Linux kernel’s OverlayFS subsystem in how a user copies a capable file from a nosuid mount into another mount. This uid mapping bug allows a local user to escalate their privileges on the system.
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 confidenceA uid mapping bug in the Linux kernel's OverlayFS subsystem allows local users to escalate privileges by copying a setuid file with capabilities from a nosuid mount into another mount, bypassing security restrictions.
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
Debian LinuxOperating system
= 10.0
Ubuntu LinuxOperating system
= 18.04= 20.04= 22.04
Linux KernelOperating system
>= 5.11, < 5.15.91>= 5.16, < 6.1.9= 6.2all versionsall versionsall versionsall versionsall versionsCVSS 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
- High
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/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 checksWork through these to decide whether this CVE applies to you.
-
Check kernel versionRun 'uname -r' to get the running kernel version, then compare it to the affected ranges: >= 5.11 and < 5.15.91, >= 5.16 and < 6.1.9, or exactly 6.2Affected if The kernel version falls within any of the affected version ranges
-
Verify OverlayFS is in useRun 'mount | grep overlay' to see if OverlayFS is currently mounted on the systemAffected if OverlayFS is mounted and the kernel version is vulnerable
-
Check for nosuid on OverlayFS mountsRun 'mount | grep overlay' and examine the mount options column for each OverlayFS mount; look for 'nosuid' in the optionsAffected if OverlayFS is mounted without the nosuid option and a setuid file with capabilities exists on the underlying layer
-
Identify setuid binaries with capabilitiesRun 'getcap -r /' to recursively search for files with capabilities, then check which of those also have the setuid bit set using 'ls -l <file>'Affected if The system has setuid files that also possess capabilities, combined with vulnerable kernel and unprotected OverlayFS
A system is affected if it runs a vulnerable kernel version (5.11-5.15.91, 5.16-6.1.9, or 6.2), uses OverlayFS without the nosuid option on mounts containing setuid files with capabilities.
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 · scoped5.15.916.1.9
Apply the corresponding kernel security patch and update to a patched kernel version; reboot affected systems to load the fixed kernel.
Linux Kernel >= 5.15.91 (for 5.x branch), >= 6.1.9 (for 6.x branch), or >= 6.2.1; Ubuntu 18.04/20.04/22.04 via apt security updates; Debian 11+
- For Ubuntu systems: Run 'sudo apt update && sudo apt upgrade linux-image-generic' to install the latest patched kernel from Ubuntu security repositories
- After kernel upgrade, reboot the system: 'sudo reboot'
- Verify the running kernel version with 'uname -r' and confirm it is >= 5.15.91, >= 6.1.9, or >= 6.2.1 (depending on your kernel branch)
- For Debian 10 (Buster): Consider upgrading to Debian 11 or 12 for kernel support, or check for backported security updates via 'apt-get update && apt-get upgrade'
- For embedded/IoT devices with H-series firmware: Contact the device vendor for firmware updates addressing this vulnerability
Generated from the published advisory — verify against the referenced sources before acting.
Fix this in Debian Linux
Exploited in the wild — priority engagement
- Consultation6.0 h
- Implementation12.0 h
- Testing8.0 h
- Review / QA4.0 h
An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $8,448.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2023-0386 — 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-2023-0386 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