CVE-2021-3911 Explained : Impact and Mitigation

If the ROA that a repository returns contains too many bits for the IP address, then OctoRPKI will crash.

Understanding CVE-2021-3911

This CVE-2021-3911 involves a vulnerability in OctoRPKI, a product by Cloudflare, where a misconfigured IP address field in Route Origin Authorization (ROA) response can lead to a system crash.

What is CVE-2021-3911?

The CVE-2021-3911 vulnerability occurs when the ROA received contains excessive bits for the IP address, causing OctoRPKI to crash due to improper handling of this data.

The Impact of CVE-2021-3911

With a CVSS base score of 4.2 (Medium severity), this vulnerability can result in a denial of service (DoS) condition, impacting the availability of the OctoRPKI service.

Technical Details of CVE-2021-3911

This section provides more in-depth technical insights into the CVE-2021-3911 vulnerability.

Vulnerability Description

The flaw lies in the processing of ROA responses by OctoRPKI, where an overflow of bits in the IP address field triggers a crash, potentially leading to a service outage.

Affected Systems and Versions

The affected product is OctoRPKI by Cloudflare, with versions lower than 1.4.0 being susceptible to this vulnerability.

Exploitation Mechanism

Exploitation requires an attacker to craft a malicious ROA response with an excessively large IP address field, leading to a crash in the OctoRPKI service.

Mitigation and Prevention

To secure systems from CVE-2021-3911, immediate actions and long-term security practices are recommended.

Immediate Steps to Take

Upgrade OctoRPKI to version 1.4 or higher to mitigate the vulnerability.

Long-Term Security Practices

Regularly check for updates and patches for OctoRPKI to address any potential security issues.

Patching and Updates

Keep the OctoRPKI software up to date with the latest security patches and fixes to prevent exploitation of known vulnerabilities.