CVE-2021-3909
4.4 · MEDIUMOverview
CVE-2021-3909 is a medium-severity vulnerability affecting cloudflare octorpki. It was published on November 11, 2021 and has a CVSS 3.1 base score of 4.4 (MEDIUM).
This vulnerability has a CVSS 3.1 base score of 4.4, rated MEDIUM. It can be exploited remotely over the network. Some level of privileges is required for exploitation.
Technical Description
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.
Remediation
Check the references section for vendor advisories and patches from cloudflare. Update octorpki to the latest patched version. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.
Affected Products
| Vendor | Product | Versions | Status |
|---|---|---|---|
| cloudflare | octorpki | >= 0, < 1.3.0 | Affected |
References
Frequently Asked Questions
What is CVE-2021-3909?
CVE-2021-3909 is a medium-severity vulnerability affecting cloudflare octorpki. It was published on November 11, 2021 and has a CVSS 3.1 base score of 4.4 (MEDIUM).
How severe is CVE-2021-3909?
This vulnerability has a CVSS 3.1 base score of 4.4, rated MEDIUM. It can be exploited remotely over the network. Some level of privileges is required for exploitation.
How do I fix or remediate CVE-2021-3909?
Check the references section for vendor advisories and patches from cloudflare. Update octorpki to the latest patched version. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.
How can CyberStrike help with CVE-2021-3909?
CyberStrike's AI-powered security agents can automatically detect CVE-2021-3909 across your infrastructure using autonomous pentesting, DAST scanning, and HackBrowser. The platform continuously monitors for known vulnerabilities and provides actionable remediation guidance prioritized by real-world exploitability.
How CyberStrike Helps
AI agents map your attack surface to find vulnerabilities like this one.
Automated penetration testing that runs continuously, not just quarterly.
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Browser-based exploitation validates findings with real proof-of-concept.
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