dbcve.org
FreeBSDOperating system

CVE-2022-23085

HIGH · 8.2 CVSS v3.1 Published 2024-02-15
Fix available
A fix is available. Upgrade to 12.3 or later.
See remediation →
84/100
Remediation priority · High
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
A user-provided integer option was passed to nmreq_copyin() without checking if it would overflow. This insufficient bounds checking could lead to kernel memory corruption. On systems configured to include netmap in their devfs_ruleset, a privileged process running in a jail can affect the host environment.

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 confidence

Integer overflow in nmreq_copyin() in the netmap kernel module allows a user-provided integer to be used without proper bounds checking, leading to kernel memory corruption. On systems with netmap in devfs_ruleset, a privileged process in a jail can escape to affect the host environment.

MitigationRemove netmap from devfs_ruleset or disable netmap if not required; otherwise apply vendor patch to add proper bounds checking to nmreq_copyin().

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:>= 12.0, < 12.3= 12.3= 13.0

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
Local
Complexity
Low
Privileges
High
User interaction
None
Scope
Changed
Confidentiality
High
Integrity
High
Availability
High

CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:C/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 checks

Work through these to decide whether this CVE applies to you.

  1. Check FreeBSD version
    Run `freebsd-version -k` or `uname -r` to determine the installed kernel version
    Affected if The version is 12.0 through 12.2, exactly 12.3, or exactly 13.0
  2. Verify netmap kernel module is loaded
    Run `kldstat | grep -i netmap` to check if the netmap module is currently loaded in the kernel
    Affected if The netmap module appears in the output, indicating it is loaded
  3. Check if netmap is enabled at boot
    Examine /boot/loader.conf and /etc/rc.conf for lines containing 'netmap_load' or 'netmap_enable'
    Affected if netmap is enabled to load at boot time (netmap_load="YES" or similar configuration present)
  4. Inspect devfs_ruleset configuration for netmap
    Check /etc/rc.conf for devfs_ruleset assignments related to netmap, or examine the system's devfs configuration: `devctl set` commands or jail configurations that map netmap into jail namespaces
    Affected if netmap is assigned to a devfs_ruleset that makes it accessible from within a jail context

A system is affected if it runs a vulnerable FreeBSD version (12.0-12.3 or 13.0) with the netmap kernel module loaded or enabled, particularly if netmap is exposed via devfs_ruleset to jail environments.

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.

dbcve · scoped
Upgrade available Upgrade to 12.3 or later
Fixed in 12.3
Interim mitigation

Remove netmap from devfs_ruleset or disable netmap if not required; otherwise apply vendor patch to add proper bounds checking to nmreq_copyin().

Recommended fix High confidence

FreeBSD 12.4-RELEASE or later for 12.x branch; FreeBSD 13.1-RELEASE or later for 13.x branch

  1. 1. Identify the currently running FreeBSD version using 'freebsd-version' or 'uname -a'
  2. 2. If running FreeBSD 12.x (12.0 through 12.3), plan upgrade to FreeBSD 12.4-RELEASE or later
  3. 3. If running FreeBSD 13.0, plan upgrade to FreeBSD 13.1-RELEASE or later
  4. 4. Review FreeBSD upgrade instructions at https://www.freebsd.org/releases/
  5. 5. Perform a full backup of all critical data before upgrading
  6. 6. Apply the upgrade using 'freebsd-update' or by rebuilding from source
  7. 7. Reboot the system into the new kernel
  8. 8. Verify the running version matches the expected fixed release
Caveat Major FreeBSD upgrades may require checking application compatibility and updating configuration files; review release notes before upgrading

Generated from the published advisory — verify against the referenced sources before acting.

Fix this in FreeBSD Scoped from the published advisory
  • Consultation6.0 h
  • Implementation12.0 h
  • Testing8.0 h
  • Review / QA6.0 h
32.0 hours of engineering $5,640
Get the upgrade done

An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $9,024.

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-2022-23085 in production — separate from our analysis above.

No notes yet

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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