CVE-2023-25564

GSS-NTLMSSP vulnerable to memory corruption when decoding UTF16 strings

HIGH
8.2
CVSS Score
Published: February 14, 2023 at 05:35 PM UTC
Updated: June 17, 2026 at 05:41 AM UTC
2 products affected across 2 vendorsGss NtlmsspNtlmssp Project Gss Ntlmssp

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Severity
HIGH8.2
Exploit prediction
EPSS 2%
SSVC
No known exploit

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.

Affected

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

v < 1.2.0
Affected range stops below 1.2.0, so it looks safe — our inference, not a vendor statement
v < 1.2.0
Affected range stops below 1.2.0, so it looks safe — our inference, not a vendor statement

Remediation

No guide yet

No remediation guidance has been written for this CVE yet. What the record does show:

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
LOW
Privileges
NONE
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
NONE
Integrity
LOW
Availability
HIGH
Vector?

Quick Info

StatusMODIFIED
CWE
CWE-787

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