CVE-2023-25564

Name: CVE-2023-25564
Creator: NVD / NIST
Published: 2023-02-14T18:15:13.173+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

HIGHCVSS 8.2/10EPSS 1.94%

Last modified Jun 17, 2026

CVE-2023-25564 is a high-severity vulnerability rated 8.2/10 on the CVSS scale. GSS-NTLMSSP is a mechglue plugin for the GSSAPI library that implements NTLM authentication. Prior to version 1.2.0, memory corruption can be triggered when decoding UTF16 strings. EPSS estimates a 1.94% chance of exploitation in the next 30 days.

Description

GSS-NTLMSSP is a mechglue plugin for the GSSAPI library that implements NTLM authentication. Prior to version 1.2.0, memory corruption can be triggered when decoding UTF16 strings. The variable `outlen` was not initialized and could cause writing a zero to an arbitrary place in memory if `ntlm_str_convert()` were to fail, which would leave `outlen` uninitialized. This can lead to a denial of service if the write hits unmapped memory or randomly corrupts a byte in the application memory space. This vulnerability can trigger an out-of-bounds write, leading to memory corruption. This vulnerability can be triggered via the main `gss_accept_sec_context` entry point. This issue is fixed in version 1.2.0.

Metrics

CVSS 3.1

8.2/10

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:H

EPSS Probability

1.94%

77.6th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

Affected Software

Vendor	Product	Versions
Gss-Ntlmssp Project	Gss-Ntlmssp	< 1.2.0

References

https://github.com/gssapi/gss-ntlmssp/commit/c753000eb31835c0664e528fbc99378ae0cbe950Patch, Third Party Advisory
https://github.com/gssapi/gss-ntlmssp/releases/tag/v1.2.0Third Party Advisory
https://github.com/gssapi/gss-ntlmssp/security/advisories/GHSA-r85x-q5px-9xfqThird Party Advisory
https://github.com/gssapi/gss-ntlmssp/commit/c753000eb31835c0664e528fbc99378ae0cbe950Patch, Third Party Advisory
https://github.com/gssapi/gss-ntlmssp/releases/tag/v1.2.0Third Party Advisory
https://github.com/gssapi/gss-ntlmssp/security/advisories/GHSA-r85x-q5px-9xfqThird Party Advisory

Timeline

Published: Feb 14, 2023
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2023-25564?

How severe is CVE-2023-25564?

CVE-2023-25564 has a CVSS score of 8.2/10 (HIGH severity). The EPSS model estimates a 1.94% probability of exploitation in the next 30 days.

How do I fix CVE-2023-25564?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2023-25564?

Run a free Strix scan to check your systems for this vulnerability.

Scan your code now

Source: NVD / NIST