Bug 2393958 (CVE-2025-59089)
| Summary: | CVE-2025-59089 python-kdcproxy: Remote DoS via unbounded TCP upstream buffering | ||
|---|---|---|---|
| Product: | [Other] Security Response | Reporter: | Pedro Sampaio <psampaio> |
| Component: | vulnerability | Assignee: | Product Security DevOps Team <prodsec-dev> |
| Status: | NEW --- | QA Contact: | |
| Severity: | medium | Docs Contact: | |
| Priority: | medium | ||
| Version: | unspecified | CC: | security-response-team |
| Target Milestone: | --- | Keywords: | Security |
| Target Release: | --- | ||
| Hardware: | All | ||
| OS: | Linux | ||
| Whiteboard: | |||
| Fixed In Version: | Doc Type: | --- | |
| Doc Text: |
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.
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Story Points: | --- |
| Clone Of: | Environment: | ||
| Last Closed: | Type: | --- | |
| Regression: | --- | Mount Type: | --- |
| Documentation: | --- | CRM: | |
| Verified Versions: | Category: | --- | |
| oVirt Team: | --- | RHEL 7.3 requirements from Atomic Host: | |
| Cloudforms Team: | --- | Target Upstream Version: | |
| Embargoed: | |||
| Bug Depends On: | 2414552, 2414553, 2415860 | ||
| Bug Blocks: | |||
| Deadline: | 2025-11-12 | ||
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Description
Pedro Sampaio
2025-09-08 21:41:36 UTC
This issue has been addressed in the following products: Red Hat Enterprise Linux 10.0 Extended Update Support Via RHSA-2025:21141 https://access.redhat.com/errata/RHSA-2025:21141 This issue has been addressed in the following products: Red Hat Enterprise Linux 10 Via RHSA-2025:21142 https://access.redhat.com/errata/RHSA-2025:21142 This issue has been addressed in the following products: Red Hat Enterprise Linux 9 Via RHSA-2025:21139 https://access.redhat.com/errata/RHSA-2025:21139 This issue has been addressed in the following products: Red Hat Enterprise Linux 9.6 Extended Update Support Via RHSA-2025:21138 https://access.redhat.com/errata/RHSA-2025:21138 This issue has been addressed in the following products: Red Hat Enterprise Linux 8 Via RHSA-2025:21140 https://access.redhat.com/errata/RHSA-2025:21140 This issue has been addressed in the following products: Red Hat Enterprise Linux 9.2 Update Services for SAP Solutions Via RHSA-2025:21448 https://access.redhat.com/errata/RHSA-2025:21448 This issue has been addressed in the following products: Red Hat Enterprise Linux 9.4 Extended Update Support Via RHSA-2025:21748 https://access.redhat.com/errata/RHSA-2025:21748 This issue has been addressed in the following products: Red Hat Enterprise Linux 9.0 Update Services for SAP Solutions Via RHSA-2025:21806 https://access.redhat.com/errata/RHSA-2025:21806 This issue has been addressed in the following products: Red Hat Enterprise Linux 8.2 Advanced Update Support Via RHSA-2025:21821 https://access.redhat.com/errata/RHSA-2025:21821 This issue has been addressed in the following products: Red Hat Enterprise Linux 8.4 Advanced Mission Critical Update Support Red Hat Enterprise Linux 8.4 Extended Update Support Long-Life Add-On Via RHSA-2025:21820 https://access.redhat.com/errata/RHSA-2025:21820 This issue has been addressed in the following products: Red Hat Enterprise Linux 8.6 Advanced Mission Critical Update Support Red Hat Enterprise Linux 8.6 Update Services for SAP Solutions Red Hat Enterprise Linux 8.6 Telecommunications Update Service Via RHSA-2025:21819 https://access.redhat.com/errata/RHSA-2025:21819 This issue has been addressed in the following products: Red Hat Enterprise Linux 8.8 Update Services for SAP Solutions Red Hat Enterprise Linux 8.8 Telecommunications Update Service Via RHSA-2025:21818 https://access.redhat.com/errata/RHSA-2025:21818 This issue has been addressed in the following products: Red Hat Enterprise Linux 7 Extended Lifecycle Support Via RHSA-2025:22982 https://access.redhat.com/errata/RHSA-2025:22982 |