CVE-2025-6444
ServiceStack GetErrorResponse Improper Input Validation NTLM Relay Vulnerability
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.
Attack profile
How easy it is to exploit
- Attack vector
- Network
- Complexity
- High
- Privileges needed
- None
- User interaction
- None
What an attacker can affect
- Confidentiality
- High
- Integrity
- None
- Availability
- None
Exploit likelihood
What each source reports
CVE List Score used
ServiceStack GetErrorResponse Improper Input Validation NTLM Relay Vulnerability
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.
- Record
CVE-2025-6444- CVSS 3.0
- 5.9 Medium
CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N - Weakness
- CWE-20
- Updated
- 2026-11-02
EUVDEUVD-2025-19133
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.
- Record
EUVD-2025-19133- CVSS 3.0
- 5.9 Medium
CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N - Updated
- 2026-11-02
GitHub AdvisoriesGHSA-2cp7-3mjq-769q
ServiceStack GetErrorResponse Improper Input Validation NTLM Relay Vulnerability. This...
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.
- Record
GHSA-2cp7-3mjq-769q- CVSS 3.0
- 5.9 Medium
CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N - Weakness
- CWE-20
- Updated
- 2026-11-02
NVD
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.
- Record
CVE-2025-6444- CVSS 3.1
- 5.9 Medium
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N - CVSS 3.0
- 5.9 Medium
CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N - Weakness
- CWE-20
- Updated
- 2026-11-02
OSV
ServiceStack GetErrorResponse Improper Input Validation NTLM Relay Vulnerability
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.
- Record
CVE-2025-6444- CVSS 3.0
- 5.9 Medium
CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N - Weakness
- CWE-20
- Updated
- 2026-11-02
Affected products
History
| Recorded | Changed | Sources |
|---|---|---|
| first indexed | CVE List, EUVD, GitHub Advisories, NVD, OSV |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2025-6444 is a medium vulnerability (CVSS 5.9) in Servicestack, published June 25, 2025. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.49%, the 42nd percentile. No source names a fixed version.