CVE-2021-3908 Infinite certificate chain depth results in OctoRPKI running forever

What is CVE-2021-3908?

CVE-2021-3908 is a medium-severity denial of service vulnerability in Debian Debian Linux, published on 11 Nov 2021. An attacker can exploit it over the internet without logging in, with no action from the victim.

Official description

OctoRPKI does not limit the depth of a certificate chain, allowing for a CA to create children in an ad-hoc fashion, thereby making tree traversal never end.

Weakness: CWE-835, CWE-400

Which versions are affected by CVE-2021-3908?

3 open source packages ship an affected version, including github.com/cloudflare/cfrpki. It affects 2 products.

Products include Cloudflare Octorpki, Debian Debian Linux.

How do I fix CVE-2021-3908?

Upgrade github.com/cloudflare/cfrpki to 1.4.0 or later.

Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.

Is CVE-2021-3908 being exploited?

There is no known exploitation of CVE-2021-3908 in the wild and no public exploit code.

Other vulnerabilities in Debian Debian Linux

• CVE-2021-3978 Improper Preservation of Permissions in github.com/cloudflare/cfrpki/cmd/octorpki High 7.5
• CVE-2021-3761 OctoRPKI lacks contextual out-of-bounds check when validating RPKI ROA maxLength values High 7.5
• CVE-2021-3907 Arbitrary filepath traversal via URI injection High 7.4
• CVE-2022-3616 OctoRPKI crash when maximum iterations number is reached Medium 5.4
• CVE-2021-3909 Infinite open connection causes OctoRPKI to hang forever Medium 4.4

All Debian Debian Linux vulnerabilities

Sources

• CVE record
• NVD
• OSV
• GitHub advisory
• How this page is made

Also known as DEBIAN-CVE-2021-3908, GHSA-g5gj-9ggf-9vmq, GO-2022-0249.