CVE-2025-59088

If kdcproxy receives a request for a realm which does not have server addresses defined in its configuration, by default, it will query SRV records in the DNS zone matching the requested realm name. This creates a server-side request forgery vulnerability, since an attacker could send a request for a realm matching a DNS zone where they created SRV records pointing to arbitrary ports and hostnames (which may resolve to loopback or internal IP addresses). This vulnerability can be exploited to probe internal network topology and firewall rules, perform port scanning, and exfiltrate data. Deployments where the "use_dns" setting is explicitly set to false are not affected.

The CVSS score(s) listed for this vulnerability do not reflect the associated product's status, and are included for informational purposes to better understand the severity of this vulnerability.

To mitigate this issue before a final fix can be applied, set "use_dns" parameter to false in the global section of the kdcproxy.conf file. This will disable the use of DNS to find Active Directory servers so it may break the service if DNS is needed.