CVE-2025-6444

ServiceStack GetErrorResponse Improper Input Validation NTLM Relay Vulnerability

MEDIUM
5.9
CVSS Score
Published: June 25, 2025 at 05:41 PM UTC
Updated: June 17, 2026 at 10:01 AM UTC
1 product affected across 1 vendorServiceStack

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Severity
MEDIUM5.9
Exploit prediction
EPSS 0.5%
SSVC
No known exploit

Description

ServiceStack GetErrorResponse Improper Input Validation NTLM Relay Vulnerability. This vulnerability allows remote attackers to relay NTLM credentials on affected installations of ServiceStack. Interaction with this library is required to exploit this vulnerability but attack vectors may vary depending on the implementation. The specific flaw exists within the implementation of the GetErrorResponse method. The issue results from the lack of proper validation of user-supplied data, which can result in a type confusion condition. An attacker can leverage this vulnerability to relay NTLM credentials in the context of the current user. Was ZDI-CAN-25834.

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

v < 8.68.4.0
Affected range stops below 8.6, so it looks safe — our inference, not a vendor statement

Remediation

No guide yet

No remediation guidance has been written for this CVE yet, and no fixed version or vendor advisory is recorded against it.

References (1)

SSVC — Action Prioritization

SSVCNo known exploitNot automatablePartial impact

SSVC signals action urgency (what to patch first), separate from CVSS which measures severity.

CVSS

Attack Vector
NETWORK
Complexity
HIGH
Privileges
NONE
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
HIGH
Integrity
NONE
Availability
NONE
Vector?

Quick Info

StatusANALYZED
CWE
CWE-20

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