Is CVE-2022-3204 being actively exploited?

It is not currently in CISA's KEV catalog. Its EPSS exploitation probability is 1%.

What products does CVE-2022-3204 affect?

Tracked products affected include Unbound. Check the version you run to see whether it is affected.

How do I fix CVE-2022-3204?

Apply the vendor fix promptly. Upgrade affected products to a fixed version.

CVE-2022-3204

Q: What is CVE-2022-3204?

CVE-2022-3204 is a high-severity software vulnerability (Uncontrolled resource consumption) with a CVSS score of 7.5. A vulnerability named 'Non-Responsive Delegation Attack' (NRDelegation Attack) has been discovered in various DNS resolving software. The NRDelegation Attack works by having a malicious delegation with a considerable number of non responsiv

HIGH severity · CVSS 7.5 · Uncontrolled resource consumption

7.5CVSS HIGH

Summary

A vulnerability named 'Non-Responsive Delegation Attack' (NRDelegation Attack) has been discovered in various DNS resolving software. The NRDelegation Attack works by having a malicious delegation with a considerable number of non responsive nameservers. The attack starts by querying a resolver for a record that relies on those unresponsive nameservers. The attack can cause a resolver to spend a lot of time/resources resolving records under a malicious delegation point where a considerable number of unresponsive NS records reside. It can trigger high CPU usage in some resolver implementations that continually look in the cache for resolved NS records in that delegation. This can lead to degraded performance and eventually denial of service in orchestrated attacks. Unbound does not suffer from high CPU usage, but resources are still needed for resolving the malicious delegation. Unbound will keep trying to resolve the record until hard limits are reached. Based on the nature of the attack and the replies, different limits could be reached. From version 1.16.3 on, Unbound introduces fixes for better performance when under load, by cutting opportunistic queries for nameserver discovery and DNSKEY prefetching and limiting the number of times a delegation point can issue a cache lookup for missing records.

Impact & exploitability

Attack vectorNetwork

Attack complexityLow

Privileges requiredNone

User interactionNone

Confidentiality impactNone

Integrity impactNone

Availability impactHigh

Exploit probability (EPSS)1%

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Affected products we track (1)

Unbound

Recommendation

Apply the vendor fix promptly. Open any affected product above for its exact safe version.

CVE-2022-3204

Summary

Impact & exploitability

Affected products we track (1)

Recommendation

Additional information