What is CVE-2021-3761?

CVE-2021-3761 is a vulnerability in OctoRPKI prior to version 1.3.0 that allows any CA issuer in the RPKI to trick OctoRPKI into emitting an invalid VRP "MaxLength" value, causing RTR sessions to terminate.

What is the severity of CVE-2021-3761?

CVE-2021-3761 has a severity rating of high, with a CVSS score of 7.5.

How can I fix CVE-2021-3761?

To fix CVE-2021-3761, update OctoRPKI to version 1.3.0 or later.

Where can I find more information about CVE-2021-3761?

You can find more information about CVE-2021-3761 at the following references: [1] [2] [3]

Vulnerability/
CVE-2021-3761

high

7.5

CWE

787

9/9/2021

17/9/2024

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

Q: How does CVE-2021-3761 affect the victim network?

CVE-2021-3761 can be used to disable RPKI Origin Validation in a victim network (for example AS 13335 - Cloudflare) prior to launching a BGP hijack.

First published: Thu Sep 09 2021(Updated: )

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.

Credit: cna@cloudflare.com

Affected Software	Affected Version	How to fix
debian/cfrpki		1.4.2-1~deb11u1 1.4.4-1 1.5.10-2
Cloudflare Octorpki	<1.3.0
Debian Debian Linux	=11.0

Remedy

https://github.com/cloudflare/cfrpki/security/advisories/GHSA-c8xp-8mf3-62h9

Remedy

Upgrade to 1.3.0

Never miss a vulnerability like this again

Reference Links

Frequently Asked Questions

What is CVE-2021-3761?
CVE-2021-3761 is a vulnerability in OctoRPKI prior to version 1.3.0 that allows any CA issuer in the RPKI to trick OctoRPKI into emitting an invalid VRP "MaxLength" value, causing RTR sessions to terminate.
How does CVE-2021-3761 affect the victim network?
CVE-2021-3761 can be used to disable RPKI Origin Validation in a victim network (for example AS 13335 - Cloudflare) prior to launching a BGP hijack.
What is the severity of CVE-2021-3761?
CVE-2021-3761 has a severity rating of high, with a CVSS score of 7.5.
How can I fix CVE-2021-3761?
To fix CVE-2021-3761, update OctoRPKI to version 1.3.0 or later.
Where can I find more information about CVE-2021-3761?
You can find more information about CVE-2021-3761 at the following references: [1] [2] [3]

collector/security-tracker-debian
collector/nvd-index
agent/type
agent/softwarecombine
collector/mitre-cve
source/MITRE
agent/remedy
agent/references
agent/title
agent/author
agent/weakness
agent/last-modified-date
agent/severity
agent/tags
agent/description
agent/first-publish-date
agent/event
package-manager/debian
vendor/cloudflare
canonical/cloudflare octorpki
vendor/debian
canonical/debian debian linux
version/debian debian linux/11.0

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