CVE-2025-59088: Python-kdcproxy: unauthenticated ssrf via realm‑controlled dns srv

Severity: high (CVSS 8.6 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.5% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2025-11-12 · updated 2026-06-30
Weakness: CWE-918

Description

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.

Affected products

latchset kdcproxy: before 1.1.0 — fixed in 1.1.0
Red Hat Enterprise Linux 10: all versions — fixed in 0:1.0.0-19.el10_1
Red Hat Enterprise Linux 10.0 Extended Update Support: all versions — fixed in 0:1.0.0-19.el10_0
Red Hat Enterprise Linux 7 Extended Lifecycle Support: all versions — fixed in 0:0.3.2-3.el7_9.3
Red Hat Enterprise Linux 8: all versions — fixed in 8100020251028161822.823393f5, 8100020251103113748.143e9e98
Red Hat Enterprise Linux 8.2 Advanced Update Support: all versions — fixed in 8020020251106022345.792f4060
Red Hat Enterprise Linux 8.4 Advanced Mission Critical Update Support: all versions — fixed in 8040020251103205102.5b01ab7e
Red Hat Enterprise Linux 8.4 Extended Update Support Long-Life Add-On: all versions — fixed in 8040020251103205102.5b01ab7e
Red Hat Enterprise Linux 8.6 Advanced Mission Critical Update Support: all versions — fixed in 8060020251030180424.ada582f1
Red Hat Enterprise Linux 8.6 Telecommunications Update Service: all versions — fixed in 8060020251030180424.ada582f1
Red Hat Enterprise Linux 8.6 Update Services for SAP Solutions: all versions — fixed in 8060020251030180424.ada582f1
Red Hat Enterprise Linux 8.8 Telecommunications Update Service: all versions — fixed in 8080020251029082621.b0a6ceea
Red Hat Enterprise Linux 8.8 Update Services for SAP Solutions: all versions — fixed in 8080020251029082621.b0a6ceea
Red Hat Enterprise Linux 9: all versions — fixed in 0:1.0.0-9.el9_7
Red Hat Enterprise Linux 9.0 Update Services for SAP Solutions: all versions — fixed in 0:1.0.0-7.el9_0.1
Red Hat Enterprise Linux 9.2 Update Services for SAP Solutions: all versions — fixed in 0:1.0.0-7.el9_2.1
Red Hat Enterprise Linux 9.4 Extended Update Support: all versions — fixed in 0:1.0.0-7.el9_4.1
Red Hat Enterprise Linux 9.6 Extended Update Support: all versions — fixed in 0:1.0.0-9.el9_6

How to fix

Upgrade to a fixed version: latchset kdcproxy 1.1.0; Red Hat Enterprise Linux 10 0:1.0.0-19.el10_1; Red Hat Enterprise Linux 10.0 Extended Update Support 0:1.0.0-19.el10_0; Red Hat Enterprise Linux 7 Extended Lifecycle Support 0:0.3.2-3.el7_9.3; Red Hat Enterprise Linux 8 8100020251028161822.823393f5, 8100020251103113748.143e9e98; Red Hat Enterprise Linux 8.2 Advanced Update Support 8020020251106022345.792f4060; Red Hat Enterprise Linux 8.4 Advanced Mission Critical Update Support 8040020251103205102.5b01ab7e; Red Hat Enterprise Linux 8.4 Extended Update Support Long-Life Add-On 8040020251103205102.5b01ab7e; Red Hat Enterprise Linux 8.6 Advanced Mission Critical Update Support 8060020251030180424.ada582f1; Red Hat Enterprise Linux 8.6 Telecommunications Update Service 8060020251030180424.ada582f1; Red Hat Enterprise Linux 8.6 Update Services for SAP Solutions 8060020251030180424.ada582f1; Red Hat Enterprise Linux 8.8 Telecommunications Update Service 8080020251029082621.b0a6ceea. Check the vendor advisory for mitigations.

References

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