# CVE-2021-43172: rpki-client: NLnet Labs Routinator prior to 0.10.2 happily processes a chain of RRDP repositories of infinite length causing it to...

CVE-2021-43172 is fixed in rpki-client on 1 platform, first by DEBIAN-CVE-2021-43172, released November 9, 2021. It is not reported as exploited. Patch Radar priority: High.

- Web page: https://patchblox.com/security/cve/CVE-2021-43172
- Priority: High
- CVSS: 7.5 (high)
- EPSS: 0.0110
- CISA KEV: not listed
- Exploited (vendor report): no
- Publicly disclosed: no
- Published: Nov 9, 2021

## Description

NLnet 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.

## Where it's fixed

| Platform | Product | Fixed in | Fix | Released |
|---|---|---|---|---|
| Linux | rpki-client Debian 12.15 (bookworm) | 7.5-1 | [DEBIAN-CVE-2021-43172](https://patchblox.com/security/data/fix/linux/debian-cve-2021-43172.md) | Nov 9, 2021 |
| Linux | rpki-client Debian 13.5 (trixie) | 7.5-1 | [DEBIAN-CVE-2021-43172](https://patchblox.com/security/data/fix/linux/debian-cve-2021-43172.md) | Nov 9, 2021 |
| Linux | rpki-client Debian 14 | 7.5-1 | [DEBIAN-CVE-2021-43172](https://patchblox.com/security/data/fix/linux/debian-cve-2021-43172.md) | Nov 9, 2021 |

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Data as of 2026-11-09T01:18:40Z UTC. Source: Patchblox Patch Radar (https://patchblox.com/security/patch-radar). Patchblox finds out-of-date software on Windows, macOS and Linux and updates it through release rings: https://patchblox.com/demo

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