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.
Metrics
Affected Vendors & Products
References
History
Thu, 13 Nov 2025 00:15:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| CPEs | cpe:/a:redhat:enterprise_linux:8 cpe:/a:redhat:enterprise_linux:9 cpe:/a:redhat:rhel_eus:9.6 |
|
| References |
| |
| Metrics |
threat_severity
|
threat_severity
|
Wed, 12 Nov 2025 22:45:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| First Time appeared |
Redhat enterprise Linux Eus
Redhat rhel Eus |
|
| CPEs | cpe:/o:redhat:enterprise_linux:8 cpe:/o:redhat:enterprise_linux:9 |
cpe:/a:redhat:enterprise_linux:8::appstream cpe:/a:redhat:enterprise_linux:9::appstream cpe:/a:redhat:rhel_eus:9.6::appstream cpe:/o:redhat:enterprise_linux:10.1 cpe:/o:redhat:enterprise_linux_eus:10.0 |
| Vendors & Products |
Redhat enterprise Linux Eus
Redhat rhel Eus |
|
| References |
|
Wed, 12 Nov 2025 21:15:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| Metrics |
ssvc
|
Wed, 12 Nov 2025 15:15:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| 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. | |
| Title | Python-kdcproxy: remote dos via unbounded tcp upstream buffering | |
| First Time appeared |
Redhat
Redhat enterprise Linux |
|
| Weaknesses | CWE-770 | |
| CPEs | cpe:/o:redhat:enterprise_linux:10 cpe:/o:redhat:enterprise_linux:7 cpe:/o:redhat:enterprise_linux:8 cpe:/o:redhat:enterprise_linux:9 |
|
| Vendors & Products |
Redhat
Redhat enterprise Linux |
|
| References |
| |
| Metrics |
cvssV3_1
|
Status: PUBLISHED
Assigner: redhat
Published:
Updated: 2025-11-12T22:33:16.651Z
Reserved: 2025-09-08T21:43:30.846Z
Link: CVE-2025-59089
Updated: 2025-11-12T20:47:47.430Z
Status : Received
Published: 2025-11-12T17:15:38.360
Modified: 2025-11-12T23:15:39.720
Link: CVE-2025-59089