CVE-2021-43172
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 · uneditedNLnet Labs Routinator prior to 0.10.2 happily processes a chain of RRDP repositories of infinite length causing it to never finish a validation run. In RPKI, a CA can choose the RRDP repository it wishes to publish its data in. By continuously generating a new child CA that only consists of another CA using a different RRDP repository, a malicious CA can create a chain of CAs of de-facto infinite length. Routinator prior to version 0.10.2 did not contain a limit on the length of such a chain and will therefore continue to process this chain forever. As a result, the validation run will never finish, leading to Routinator continuing to serve the old data set or, if in the initial validation run directly after starting, never serve any data at all.
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 confidenceRoutinator prior to 0.10.2 lacks a limit on the length of RRDP repository chains during RPKI validation. A malicious CA can exploit this by creating a chain of child CAs, each using a different RRDP repository, causing infinite recursion that prevents validation from completing.
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< 0.10.2CVSS 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
- None
- Availability
- High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/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 if Routinator is installedRun 'routinator --version' or check for the routinator binary in common locations (/usr/bin/routinator, /usr/local/bin/routinator). On Linux, you can also use 'which routinator' or 'dpkg -l | grep routinator' if installed via package manager.Affected if Routinator is not found on the system, so the CVE does not apply.
-
Determine installed Routinator versionExecute 'routinator --version' and note the version number in the output. The format typically shows 'routinator 0.x.x' where x.x is the version.Affected if Unable to determine version, manual inspection required.
-
Compare version against vulnerable rangeCompare the installed version number to 0.10.2. Any version less than 0.10.2 (such as 0.10.1, 0.10.0, 0.9.x, etc.) is affected by this vulnerability.Affected if Installed version is less than 0.10.2 (for example, 0.10.1, 0.10.0, or any 0.9.x release).
The environment is affected only if Routinator is installed and the installed version is lower than 0.10.2.
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 · scoped0.10.2
Upgrade Routinator to version 0.10.2 or later, which implements a limit on RRDP repository chain length to prevent infinite loops.
0.10.2 or later
- Check current installed version of Routinator (e.g., `routinator --version`)
- Upgrade Routinator to version 0.10.2 or later using your package manager or installation method (e.g., `cargo install routinator` or your system package manager)
- Restart the Routinator service if it is running
- Verify the new version is installed and validation completes successfully
Generated from the published advisory — verify against the referenced sources before acting.
- Consultation3.0 h
- Implementation6.0 h
- Testing8.0 h
- Review / QA3.0 h
An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $5,472.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2021-43172 — 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-2021-43172 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