FedoraOperating system · Fedoraproject
CVE-2021-36377
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 · uneditedFossil before 2.14.2 and 2.15.x before 2.15.2 often skips the hostname check during TLS certificate validation.
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 · moderate confidenceFossil SCM versions before 2.14.2 and 2.15.x before 2.15.2 skip the hostname verification step during TLS certificate validation. This means the software may accept TLS certificates even when the certificate's Common Name or Subject Alternative Name does not match the hostname being connected to, allowing man-in-the-middle attackers to intercept encrypted communications using a valid certificate for a different domain.
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
= 34< 2.14.2>= 2.15.0, < 2.15.2CVSS 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
- Network
- Complexity
- Low
- Privileges
- None
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- None
- Integrity
- High
- Availability
- None
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/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.
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Determine installed Fossil SCM versionRun 'fossil version' or 'fossil --version' and note the version number displayedAffected if The reported version is less than 2.14.2, or is 2.15.0 or 2.15.1 (any version in the range >= 2.15.0 and < 2.15.2)
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Confirm Fedora version if applicableIf running on Fedora 34, check that the Fossil package version matches the affected criteria using 'rpm -q fossil' or your package managerAffected if Running Fedora 34 with any Fossil version (Fedora 34 ships the affected version)
You are affected if your installed Fossil SCM version is below 2.14.2, or is exactly 2.15.0 or 2.15.1, or if you are on Fedora 34 with the default Fossil package.
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 data2.14.22.15.2
Upgrade Fossil to version 2.14.2, 2.15.2, or later to restore proper TLS hostname verification. Until upgraded, avoid using Fossil over untrusted networks or verify certificates manually.
Fix this in Fedora
Scoped from the published advisory
- Consultation2.0 h
- Implementation2.0 h
- Testing3.0 h
- Review / QA1.0 h
An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $2,224.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2021-36377 — 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-2021-36377 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
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- 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
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