CVE-2021-43172: nlnet labs routinator Uncontrolled Recursion

Vulnerability summary

CVE-2021-43172 is a high (CVSS 7.5) Uncontrolled Recursion vulnerability in nlnet labs routinator. EPSS estimates a 1.27% chance of exploitation in the next 30 days, higher than 69.4% of scored vulnerabilities.

Timeline

1. 09-11-2021
   PublishedVulnerability first disclosed.
2. 16-09-2024
   Last modifiedVulnerability information updated.

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.

• CWE-674Uncontrolled RecursionThe product does not properly control the amount of recursion that takes place, consuming excessive resources, such as allocated memory or the program stack.
• CWE-835Loop with Unreachable Exit Condition ('Infinite Loop')The product contains an iteration or loop with an exit condition that cannot be reached, i.e., an infinite loop.