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RuncApplication · Linuxfoundation

CVE-2023-25809

MEDIUM · 6.3 CVSS v3.1 Published 2023-03-29
Fix available
A fix is available. Upgrade to 1.1.5 or later.
See remediation →
65/100
Remediation priority · Elevated
Public exploit Zero-click Patch available

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
runc is a CLI tool for spawning and running containers according to the OCI specification. In affected versions it was found that rootless runc makes `/sys/fs/cgroup` writable in following conditons: 1. when runc is executed inside the user namespace, and the `config.json` does not specify the cgroup namespace to be unshared (e.g.., `(docker|podman|nerdctl) run --cgroupns=host`, with Rootless Docker/Podman/nerdctl) or 2. when runc is executed outside the user namespace, and `/sys` is mounted with `rbind, ro` (e.g., `runc spec --rootless`; this condition is very rare). A container may gain the write access to user-owned cgroup hierarchy `/sys/fs/cgroup/user.slice/...` on the host . Other users's cgroup hierarchies are not affected. Users are advised to upgrade to version 1.1.5. Users unable to upgrade may unshare the cgroup namespace (`(docker|podman|nerdctl) run --cgroupns=private)`. This is the default behavior of Docker/Podman/nerdctl on cgroup v2 hosts. or add `/sys/fs/cgroup` to `maskedPaths`.

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

A detailed technical summary for this CVE is being prepared.

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
RuncApplication
Affected:< 1.1.5

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
Low
User interaction
None
Scope
Changed
Confidentiality
Low
Integrity
Low
Availability
Low

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:L/I:L/A:L

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 1.1.5 or later
Fixed in 1.1.5
Vendor patch github.com →
Recommended fix High confidence

runc version 1.1.5

  1. 1. Identify the current runc version installed on the system using `runc --version`
  2. 2. Obtain the fixed runc version 1.1.5 from the official opencontainers/runc GitHub releases page: https://github.com/opencontainers/runc/releases/tag/v1.1.5
  3. 3. Download the appropriate binary for your system architecture
  4. 4. Replace the existing runc binary with the new version (typically located at `/usr/bin/runc` or `/usr/local/bin/runc`)
  5. 5. Verify the installation by running `runc --version` to confirm version 1.1.5 is installed
  6. 6. For container runtimes (Docker/Podman/nerdctl), restart the runtime service if necessary to ensure the new runc binary is used
  7. 7. As an alternative mitigation if upgrading is not immediately possible, ensure containers are run with `--cgroupns=private` (default on cgroup v2 hosts) to avoid the vulnerable configuration
Caveat Upgrading runc is generally low-risk; however, ensure compatibility with your container runtime (Docker/Podman/nerdctl) and test in a non-production environment first

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

We can perform the upgrade in your staging environment and verify nothing breaks — typical engagement from $1,600. Get the upgrade done

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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-2023-25809 in production — separate from our analysis above.

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