CVE-2024-9666 Org.keycloak/keycloak-quarkus-server: keycloak proxy header handling denial-of-service (dos) vulnerability

What is CVE-2024-9666?

CVE-2024-9666 is a medium-severity denial of service vulnerability in Red Hat Build of Keycloak, published on 25 Nov 2024. It can only be exploited from the same machine or local network, with no action from the victim.

Official description

A vulnerability was found in the Keycloak Server. The Keycloak Server is vulnerable to a denial of service (DoS) attack due to improper handling of proxy headers. When Keycloak is configured to accept incoming proxy headers, it may accept non-IP values, such as obfuscated identifiers, without proper validation. This issue can lead to costly DNS resolution operations, which an attacker could exploit to tie up IO threads and potentially cause a denial of service. The attacker must have access to send requests to a Keycloak instance that is configured to accept proxy headers, specifically when reverse proxies do not overwrite incoming headers, and Keycloak is configured to trust these headers.

Weakness: CWE-444

Which versions are affected by CVE-2024-9666?

4 open source packages ship an affected version, including org.keycloak:keycloak-quarkus-server.

How do I fix CVE-2024-9666?

Upgrade org.keycloak:keycloak-quarkus-server to 26.0.6 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-2024-9666 being exploited?

There is no known exploitation of CVE-2024-9666 in the wild and no public exploit code.

Sources

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

Also known as ECHO-7edb-23c5-02ec, GHSA-jgwc-jh89-rpgq.