Trail of Bits (https://trailofbits.com) conducted a security review and threat model of CoreDNS.

Quoting from the security review summary:

“The audit uncovered one high-severity issue (TOB-CDNS-8) concerning a bug that could lead to cache poisoning attacks. The majority of the other issues are of informational or low severity; these include several resulting from insufficient data validation, specifically from assumptions about the data processed by various functions, which we discovered by running fuzzing harnesses. Most of the findings pertain to denial-of-service vulnerabilities.”

The report can be found in Trail of Bits’ publications on GitHub: https://github.com/trailofbits/publications/blob/master/reviews/CoreDNS.pdf

At this time, the following PRs have been opened to address issues raised in the report:

• https://github.com/coredns/coredns/pull/5085 (TOB-CDNS-1)
• https://github.com/coredns/coredns/pull/5108 (TOB-CDNS-5)
• https://github.com/coredns/coredns/pull/5168 (TOB-CDNS-2)
• https://github.com/coredns/coredns/pull/5169 (TOB-CDNS-3)
• https://github.com/coredns/coredns/pull/5170 (TOB-CDNS-4)
• https://github.com/coredns/coredns/pull/5171 (TOB-CDNS-15)
• https://github.com/coredns/coredns/pull/5172 (TOB-CDNS-11)
• https://github.com/coredns/coredns/pull/5173 (TOB-CDNS-9)
• https://github.com/coredns/coredns/pull/5174 (TOB-CDNS-8)
• https://github.com/coredns/coredns/pull/5220 (TOB-CDNS-10)
• https://github.com/coredns/coredns/pull/5224 (TOB-CDNS-14)
• https://github.com/coredns/coredns/pull/5225 (TOB-CDNS-7)
• https://github.com/coredns/coredns/pull/5226 (TOB-CDNS-6)
• https://github.com/coredns/coredns/pull/5227 (TOB-CDNS-12)
• https://github.com/coredns/coredns/pull/5228 (TOB-CDNS-12)
• https://github.com/coredns/coredns/pull/5231 (TOB-CDNS-12)