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5.9 Medium

CVE-2025-59089 If an attacker causes kdcproxy to connect to an attacker-controlled KDC server (e.g

Description

If an attacker causes kdcproxy to connect to an attacker-controlled KDC server (e.g. through server-side request forgery), they can exploit the fact that kdcproxy does not enforce bounds on TCP response length to conduct a denial-of-service attack. While receiving the KDC's response, kdcproxy copies the entire buffered stream into a new buffer on each recv() call, even when the transfer is incomplete, causing excessive memory allocation and CPU usage. Additionally, kdcproxy accepts incoming response chunks as long as the received data length is not exactly equal to the length indicated in the response header, even when individual chunks or the total buffer exceed the maximum length of a Kerberos message. This allows an attacker to send unbounded data until the connection timeout is reached (approximately 12 seconds), exhausting server memory or CPU resources. Multiple concurrent requests can cause accept queue overflow, denying service to legitimate clients.

Affected products and versions

Product Affected versions Fixed in
kdcproxy 1.1 earliest → < 1.1.0 1.1.0
Red Hat Enterprise Linux 10 Versions not published
Red Hat Enterprise Linux 10.0 Extended Update Support Versions not published
Red Hat Enterprise Linux 7 Extended Lifecycle Support Versions not published
Red Hat Enterprise Linux 8 8100020251028161822.823393 earliest → < 8100020251028161822.823393f5 8100020251028161822.823393f5
Red Hat Enterprise Linux 8.2 Advanced Update Support 8020020251106022345.792 earliest → < 8020020251106022345.792f4060 8020020251106022345.792f4060
Red Hat Enterprise Linux 8.4 Advanced Mission Critical Update Support 8040020251103205102.5 earliest → < 8040020251103205102.5b01ab7e 8040020251103205102.5b01ab7e
Red Hat Enterprise Linux 8.4 Extended Update Support Long-Life Add-On 8040020251103205102.5 earliest → < 8040020251103205102.5b01ab7e 8040020251103205102.5b01ab7e
Red Hat Enterprise Linux 8.6 Advanced Mission Critical Update Support 8060020251030180424 earliest → < 8060020251030180424.ada582f1 8060020251030180424.ada582f1
Show the 10 other branches
Product Affected versions Fixed in
Red Hat Enterprise Linux 8.6 Telecommunications Update Service 8060020251030180424 earliest → < 8060020251030180424.ada582f1 8060020251030180424.ada582f1
Red Hat Enterprise Linux 8.6 Update Services for SAP Solutions 8060020251030180424 earliest → < 8060020251030180424.ada582f1 8060020251030180424.ada582f1
Red Hat Enterprise Linux 8.8 Telecommunications Update Service 8080020251029082621 earliest → < 8080020251029082621.b0a6ceea 8080020251029082621.b0a6ceea
Red Hat Enterprise Linux 8.8 Update Services for SAP Solutions 8080020251029082621 earliest → < 8080020251029082621.b0a6ceea 8080020251029082621.b0a6ceea
Red Hat Enterprise Linux 9 Versions not published
Red Hat Enterprise Linux 9.0 Update Services for SAP Solutions Versions not published
Red Hat Enterprise Linux 9.2 Update Services for SAP Solutions Versions not published
Red Hat Enterprise Linux 9.4 Extended Update Support Versions not published
Red Hat Enterprise Linux 9.6 Extended Update Support Versions not published
Red Hat In-Vehicle Operating System 1 Versions not published

References

Timeline

  1. Published
  2. Last modified

Other CVEs of kdcproxy

The 2 CVEs of kdcproxy →
CVE-2025-59088 Python-kdcproxy: unauthenticated ssrf via realm‑controlled dns srv 8.6 High
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