CVE-2021-3761 HIGH

CVE-2021-3761: OctoRPKI lacks contextual out-of-bounds check when validating RPKI ROA maxLength values

Vendor Cloudflare
Product octorpki
Published September 9, 2021
Last update September 17, 2024

CVSS base score

7.5/10
Attack vector Network
Attack complexity Low
Privileges required None
User interaction None
Confidentiality None
Integrity None

CVSS vector

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

What the vulnerability does

01Description

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.

Key dates

02Disclosure timeline

September 9, 2021 CVE published
September 17, 2024 Record updated