CVE-2021-3761

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

HIGH
7.5
CVSS Score
Published: September 9, 2021 at 02:05 PM UTC
Updated: June 17, 2026 at 04:05 AM UTC
2 products affected across 2 vendorsDebian LinuxOctoRPKI

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Severity
HIGH7.5
Exploit prediction
EPSS 1%

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.

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

v < 1.3.0
Affected range stops below 1.3.0, so it looks safe — our inference, not a vendor statement

Remediation

No guide yet

No remediation guidance has been written for this CVE yet. What the record does show:

References (2)

Vendor Advisoryx_refsource_DEBIANThird Party Advisory
https://www.debian.org/security/2022/dsa-5041

CVSS

7.5HIGHcloudflare
Attack Vector
NETWORK
Complexity
LOW
Privileges
NONE
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
NONE
Integrity
NONE
Availability
HIGH
Vector?

Quick Info

StatusMODIFIED
CWE
CWE-787

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