Allocation of Resources Without Limits or Throttling The advisory has been revoked - it doesn't affect any version of package openshift4/ose-coredns-rhel9 (opens in a new tab)
Threat Intelligence
The probability is the direct output of the EPSS model, and conveys an overall sense of the threat of exploitation in the wild. The percentile measures the EPSS probability relative to all known EPSS scores. Note: This data is updated daily, relying on the latest available EPSS model version. Check out the EPSS documentation for more details.
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Test your applications- Snyk IDSNYK-RHEL8-OPENSHIFT4OSECOREDNSRHEL9-10331610
- published7 Jun 2025
- disclosed6 Jun 2025
Introduced: 6 Jun 2025
CVE-2025-47950 (opens in a new tab)Amendment
The Red Hat security team deemed this advisory irrelevant for RHEL:8.
NVD Description
Note: Versions mentioned in the description apply only to the upstream openshift4/ose-coredns-rhel9 package and not the openshift4/ose-coredns-rhel9 package as distributed by RHEL.
CoreDNS is a DNS server that chains plugins. In versions prior to 1.12.2, a Denial of Service (DoS) vulnerability exists in the CoreDNS DNS-over-QUIC (DoQ) server implementation. The server previously created a new goroutine for every incoming QUIC stream without imposing any limits on the number of concurrent streams or goroutines. A remote, unauthenticated attacker could open a large number of streams, leading to uncontrolled memory consumption and eventually causing an Out Of Memory (OOM) crash — especially in containerized or memory-constrained environments. The patch in version 1.12.2 introduces two key mitigation mechanisms: max_streams, which caps the number of concurrent QUIC streams per connection with a default value of 256; and worker_pool_size, which Introduces a server-wide, bounded worker pool to process incoming streams with a default value of 1024. This eliminates the 1:1 stream-to-goroutine model and ensures that CoreDNS remains resilient under high concurrency. Some workarounds are available for those who are unable to upgrade. Disable QUIC support by removing or commenting out the quic:// block in the Corefile, use container runtime resource limits to detect and isolate excessive memory usage, and/or monitor QUIC connection patterns and alert on anomalies.
References
- https://access.redhat.com/security/cve/CVE-2025-47950
- https://datatracker.ietf.org/doc/html/rfc9250
- https://github.com/coredns/coredns/commit/efaed02c6a480ec147b1f799aab7cf815b17dfe1
- https://github.com/coredns/coredns/security/advisories/GHSA-cvx7-x8pj-x2gw
- https://github.com/quic-go/quic-go
- https://www.usenix.org/conference/usenixsecurity23/presentation/botella