CVE-2021-3911: Panic on misconfigured IP address in github.com/cloudflare/cfrpki
Summary
CVE-2021-3911: Panic on misconfigured IP address in github.com/cloudflare/cfrpki. Affects github.com/cloudflare/cfrpki versions < 1.4.0. Fixed in 1.4.0. How to fix ↓
Also tracked for
- cfrpki · Debian:11
The same CVE-2021-3911 is tracked separately for each ecosystem and vendor. Its fix information is the same; the package and affected versions differ.
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Background
The package under scrutiny is github.com/cloudflare/cfrpki, which is written in Go. It is a library for working with RPKI (Resource Public Key Infrastructure) data. RPKI is used to secure the Internet's routing infrastructure by associating IP address blocks with the entities authorized to announce them. The cfrpki package provides functionality for validating RPKI certificates and Route Origin Authorizations (ROAs).
Vulnerability Detail
The vulnerability, identified as CVE-2021-3911, occurs in the OctoRPKI component of the cfrpki package. When a repository returns an ROA with an IP address that contains too many bits, OctoRPKI crashes. This can be exploited by an attacker to cause a denial-of-service (DoS) condition. The issue arises due to a panic triggered by a misconfigured IP address in the ROA. The vulnerability affects versions 0.0.0 to 1.3.0 of the cfrpki package.
How To Fix
Latest published version: v1.5.10 as of 23 Oct 2026
go get github.com/cloudflare/cfrpki@v1.5.10Upgrading to it may include breaking changes; the version below is the minimum fixed release for this vulnerability.
If you need the minimum change
1.4.0
This is the first release that contains the fix.
go get github.com/cloudflare/cfrpki@v1.4.0Tip — Not sure which version your app runs? Vulert can match this fix to it. Scan free →
Workaround
There is no known workaround for this vulnerability. Upgrading to the fixed version is the recommended solution.
Conclusion
In conclusion, the cfrpki package, specifically the OctoRPKI component, is vulnerable to a DoS condition caused by a panic triggered by misconfigured IP addresses in ROAs. Users should upgrade to version 1.4.0 or later to mitigate the vulnerability. For further support on vulnerability remediation, please contact DevNack.com.
See every vulnerability recorded for github.com/cloudflare/cfrpki →
FAQ
RPKI (Resource Public Key Infrastructure) is a system used to secure the Internet's routing infrastructure by associating IP address blocks with the entities authorized to announce them.
A Route Origin Authorization (ROA) is a digitally signed object that associates an IP address prefix with the entity authorized to originate routes for that prefix.
OctoRPKI is a component of the cfrpki package that is responsible for processing ROAs and validating RPKI certificates.
The vulnerability can be exploited by an attacker to cause a denial-of-service (DoS) condition, resulting in the unavailability of the affected OctoRPKI instance.
No, only versions 0.0.0 to 1.3.0 of the cfrpki package are affected. Users should upgrade to version 1.4.0 or later to fix the vulnerability.
References
Related vulnerabilities
Recent vulnerabilities recorded for github.com/cloudflare/cfrpki.
