Kubernetes CSharp Client up to 17.0.13 Kubernetes API Server certificate validation

HistoryDiffrelatejsonxmlCTI

CVSS Meta Temp Score CVSS is a standardized scoring system to determine possibilities of attacks. The Temp Score considers temporal factors like disclosure, exploit and countermeasures. The unique Meta Score calculates the average score of different sources to provide a normalized scoring system.	Current Exploit Price (≈) Our analysts are monitoring exploit markets and are in contact with vulnerability brokers. The range indicates the observed or calculated exploit price to be seen on exploit markets. A good indicator to understand the monetary effort required for and the popularity of an attack.	CTI Interest Score Our Cyber Threat Intelligence team is monitoring different web sites, mailing lists, exploit markets and social media networks. The CTI Interest Score identifies the interest of attackers and the security community for this specific vulnerability in real-time. A high score indicates an elevated risk to be targeted for this vulnerability.
6.1	$0-$5k	0.00

Summaryinfo

A vulnerability categorized as critical has been discovered in Kubernetes CSharp Client up to 17.0.13. Affected is an unknown function of the component Kubernetes API Server Handler. Executing a manipulation can lead to certificate validation. This vulnerability appears as CVE-2025-9708. The attack may be performed from remote. There is no available exploit. It is advisable to upgrade the affected component.

Detailsinfo

A vulnerability has been found in Kubernetes CSharp Client up to 17.0.13 and classified as critical. This vulnerability affects an unknown functionality of the component Kubernetes API Server Handler. The manipulation with an unknown input leads to a certificate validation vulnerability. The CWE definition for the vulnerability is CWE-295. The product does not validate, or incorrectly validates, a certificate. As an impact it is known to affect confidentiality, integrity, and availability. CVE summarizes:

A vulnerability exists in the Kubernetes C# client where the certificate validation logic accepts properly constructed certificates from any Certificate Authority (CA) without properly verifying the trust chain. This flaw allows a malicious actor to present a forged certificate and potentially intercept or manipulate communication with the Kubernetes API server, leading to possible man-in-the-middle attacks and API impersonation.

The advisory is available at groups.google.com. This vulnerability was named CVE-2025-9708 since 08/29/2025. The exploitation appears to be difficult. The attack can be initiated remotely. No form of authentication is required for a successful exploitation. The technical details are unknown and an exploit is not available. This vulnerability is assigned to T1587.003 by the MITRE ATT&CK project.

Upgrading to version 17.0.14 eliminates this vulnerability.

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Productinfo

Type

Virtualization Software

Vendor

Kubernetes

Name

CSharp Client

Version

License

open-source

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 6.2
VulDB Meta Temp Score: 6.1

VulDB Base Score: 5.6
VulDB Temp Score: 5.4
VulDB Vector: 🔒
VulDB Reliability: 🔍

CNA Base Score: 6.8
CNA Vector (kubernetes): 🔒

CVSSv2info

AV	AC	Au	C	I	A
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💳	💳	💳	💳	💳	💳
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Vector	Complexity	Authentication	Confidentiality	Integrity	Availability
Unlock	Unlock	Unlock	Unlock	Unlock	Unlock
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Unlock	Unlock	Unlock	Unlock	Unlock	Unlock

VulDB Base Score: 🔒
VulDB Temp Score: 🔒
VulDB Reliability: 🔍

Exploitinginfo

Class: Certificate validation
CWE: CWE-295 / CWE-287
CAPEC: 🔒
ATT&CK: 🔒

Physical: No
Local: No
Remote: Yes

Availability: 🔒
Status: Not defined

EPSS Score: 🔒
EPSS Percentile: 🔒

Price Prediction: 🔍
Current Price Estimation: 🔒

0-Day	Unlock	Unlock	Unlock	Unlock
Today	Unlock	Unlock	Unlock	Unlock

Threat Intelligenceinfo

Interest: 🔍
Active Actors: 🔍
Active APT Groups: 🔍

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔒

Upgrade: CSharp Client 17.0.14

Timelineinfo

08/29/2025 CVE reserved
09/17/2025 +19 days Advisory disclosed
09/17/2025 +0 days VulDB entry created
09/17/2025 +0 days VulDB entry last update

Sourcesinfo

Advisory: 134063
Status: Confirmed

CVE: CVE-2025-9708 (🔒)
GCVE (CVE): GCVE-0-2025-9708
GCVE (VulDB): GCVE-100-324598

Entryinfo

Created: 09/17/2025 07:41
Changes: 09/17/2025 07:41 (66)
Complete: 🔍
Cache ID: 216::103