Resource exhaustion in Cloudflare Octorpki

CVE-2021-3909

OctoRPKI does not limit the length of a connection, allowing for a slowloris DOS attack to take place which makes OctoRPKI wait forever. Specifically, the repository that OctoRPKI sends HTTP requests to will keep the connection open for a day before a response is returned, but does keep drip feeding new bytes to keep the connection alive.

Vulnerability class: DoS (Denial of Service)

EPSS: 0.015 (71.9th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 4.4 (Medium). Vector: CVSS:3.1/AV:N/AC:H/PR:H/UI:N/S:U/C:N/I:N/A:H.

Affected products

Weakness classification (CWE)

Public proof-of-concept exploits

References

Frequently asked questions

What is CVE-2021-3909?
CVE-2021-3909 is a medium-severity vulnerability in Cloudflare Octorpki, classified under Uncontrolled Resource Consumption. CVSS score: 4.4/10. Published 2021-11-11.
How severe is CVE-2021-3909?
Medium severity. CVSS v3 base score is 4.4 out of 10.
Is CVE-2021-3909 known to be exploited?
2 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.