CVE Catalog

CVE-2024-9666

MediumCVSS 4.7
Published: Updated: Translated: NVD NIST

Exploitation Probability (EPSS)

Low risk
0.40%

33th percentile - higher than 33% of all known CVEs

Summary

A vulnerability was found in Keycloak Server, making it vulnerable to denial of service due to improper handling of proxy headers. When configured to accept incoming proxy headers, it may accept non-IP values without validation, leading to costly DNS resolution operations that can tie up IO threads and cause DoS. The attacker must have access to a Keycloak instance configured to accept proxy headers, especially when reverse proxies do not overwrite incoming headers.

Risk Assessment

An attacker can overload the Keycloak server, causing unavailability of authentication and authorization services. This can affect all systems relying on Keycloak.

Recommendation

Configure reverse proxies to overwrite proxy headers and do not trust incoming headers. Update Keycloak to a patched version.

Other vulnerabilities in Keycloak

See all
Original NVD description (English source)

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.

Vulnerability data from NVD (NIST) · CISA KEV · EPSS