Python-kdcproxy: unauthenticated ssrf via realm‑controlled dns srv

Summary

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.

Timeline

1. Nov 12, 2025, 4:35 PM UTCCVE published
2. Nov 12, 2025, 8:48 PM UTCCISA SSVC assessment

   Exploitation: none · Automatable: yes · Technical impact: partial

3. Jun 30, 2026, 12:30 AM UTCRecord last updated

Affected versions

• kdcproxy

  fixed in 1.1.0

• python-kdcproxy

  Version range not reported

• python-kdcproxy

  Version range not reported

• python-kdcproxy

  Version range not reported

• idm:client

  Version range not reported

• idm:DL1

  Version range not reported

• idm:DL1

  Version range not reported

• idm:DL1

  Version range not reported

• idm:DL1

  Version range not reported

• idm:DL1

  Version range not reported

• idm:DL1

  Version range not reported

• idm:DL1

  Version range not reported

• idm:DL1

  Version range not reported

• idm:DL1

  Version range not reported

• python-kdcproxy

  Version range not reported

• python-kdcproxy

  Version range not reported

• python-kdcproxy

  Version range not reported

• python-kdcproxy

  Version range not reported

• python-kdcproxy

  Version range not reported

References 16