CVE-2021-3761

OctoRPKI lacks contextual out-of-bounds check when validating RPKI ROA maxLength values

Description

Any CA issuer in the RPKI can trick OctoRPKI prior to 1.3.0 into emitting an invalid VRP "MaxLength" value, causing RTR sessions to terminate. An attacker can use this to disable RPKI Origin Validation in a victim network (for example AS 13335 - Cloudflare) prior to launching a BGP hijack which during normal operations would be rejected as "RPKI invalid". Additionally, in certain deployments RTR session flapping in and of itself also could cause BGP routing churn, causing availability issues.

Remediation

Solution:

  • Upgrade to 1.3.0

Category

7.5
CVSS
Severity: High
CVSS 3.1 •
CVSS 2.0 •
EPSS 0.45%
Vendor Advisory debian.org
Affected: Cloudflare octorpki
Published at:
Updated at:

References

Link Tags
https://github.com/cloudflare/cfrpki/security/advisories/GHSA-c8xp-8mf3-62h9 third party advisory patch
https://www.debian.org/security/2022/dsa-5041 third party advisory vendor advisory

Frequently Asked Questions

What is the severity of CVE-2021-3761?
CVE-2021-3761 has been scored as a high severity vulnerability.
How to fix CVE-2021-3761?
To fix CVE-2021-3761: Upgrade to 1.3.0
Is CVE-2021-3761 being actively exploited in the wild?
As for now, there are no information to confirm that CVE-2021-3761 is being actively exploited. According to its EPSS score, there is a ~0% probability that this vulnerability will be exploited by malicious actors in the next 30 days.
What software or system is affected by CVE-2021-3761?
CVE-2021-3761 affects Cloudflare octorpki.
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