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FedoraOperating system · Fedoraproject

CVE-2021-32760

MEDIUM · 6.3 CVSS v3.1 Published 2021-07-19
Fix available
A fix is available. Upgrade to 1.4.8 / 1.5.4 or later.
See remediation →
70/100
Remediation priority · Elevated
Remotely reachable No privileges

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
containerd is a container runtime. A bug was found in containerd versions prior to 1.4.8 and 1.5.4 where pulling and extracting a specially-crafted container image can result in Unix file permission changes for existing files in the host’s filesystem. Changes to file permissions can deny access to the expected owner of the file, widen access to others, or set extended bits like setuid, setgid, and sticky. This bug does not directly allow files to be read, modified, or executed without an additional cooperating process. This bug has been fixed in containerd 1.5.4 and 1.4.8. As a workaround, ensure that users only pull images from trusted sources. Linux security modules (LSMs) like SELinux and AppArmor can limit the files potentially affected by this bug through policies and profiles that prevent containerd from interacting with specific files.

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

containerd prior to 1.4.8 and 1.5.4 contains a vulnerability where specially-crafted container images can modify Unix file permissions (including extended bits like setuid/setgid/sticky) on existing host files during image extraction, potentially causing denial of access or privilege escalation.

MitigationUpgrade containerd to version 1.4.8 or 1.5.4 or later. As additional hardening, implement SELinux or AppArmor policies to restrict containerd file access and only pull images from trusted sources.

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
FedoraOperating system
Affected:= 34
ContainerdApplication
Affected:< 1.4.8>= 1.5.0, < 1.5.4

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
Network
Complexity
Low
Privileges
None
User interaction
Required
Scope
Unchanged
Confidentiality
Low
Integrity
Low
Availability
Low

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

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. Determine installed containerd version
    Run 'containerd --version' or check the containerd package version via your OS package manager (e.g., 'rpm -q containerd' on Fedora/RHEL, 'dpkg -l containerd' on Debian/Ubuntu)
    Affected if The version is less than 1.4.8, or greater than or equal to 1.5.0 but less than 1.5.4
  2. Check if containerd service is active
    Run 'systemctl status containerd' or 'ps aux | grep containerd' to verify the containerd daemon is running
    Affected if containerd is running and the version is vulnerable per step 1
  3. Identify extracted container images
    List all container images stored in containerd by running 'crictl images -a' or checking the containerd image store directory (typically /var/lib/containerd/io.containerd.snapshotter.android.v2)
    Affected if containerd is active, the version is vulnerable, and any images have been extracted from untrusted sources since installation
  4. For Fedora 34 systems, verify package version
    Run 'rpm -q containerd' to confirm the exact Fedora-packaged version of containerd
    Affected if Running Fedora 34 with any containerd version (Fedora 34 ships a version affected by this CVE)

A system is affected if it runs containerd with a version below 1.4.8 or between 1.5.0 and 1.5.4, or is Fedora 34 with containerd installed, and has extracted or could extract untrusted container images.

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.

From vendor data
Upgrade available Upgrade to 1.4.8 / 1.5.4 or later
Fixed in 1.4.81.5.4
Interim mitigation

Upgrade containerd to version 1.4.8 or 1.5.4 or later. As additional hardening, implement SELinux or AppArmor policies to restrict containerd file access and only pull images from trusted sources.

Fix this in Fedora Scoped from the published advisory
  • Consultation3.0 h
  • Implementation6.0 h
  • Testing3.0 h
  • Review / QA2.0 h
14.0 hours of engineering $2,490
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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-2021-32760 in production — separate from our analysis above.

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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