Description
CoreDNS is a DNS server that chains plugins. In versions prior to 1.14.3, the DNS-over-HTTPS (DoH) GET path accepts oversized dns= query parameter values and performs URL query parsing, base64 decoding, and DNS message unpacking before rejecting the request. Unlike the POST path, which applies a bounded read via http.MaxBytesReader limited to 65536 bytes, the GET path has no equivalent size validation before expensive processing. A remote, unauthenticated attacker can repeatedly send oversized DoH GET requests to force high CPU usage, large transient memory allocations, and elevated garbage-collection pressure, leading to denial of service. This issue has been fixed in version 1.14.3.
Problem types
CWE-400: Uncontrolled Resource Consumption
Product status
References
github.com/...oredns/security/advisories/GHSA-63cw-r7xf-jmwr
github.com/...oredns/security/advisories/GHSA-63cw-r7xf-jmwr
github.com/coredns/coredns/releases/tag/v1.14.3