CVE-2023-25563

GSS-NTLMSSP vulnerable to multiple out-of-bounds reads when decoding NTLM fields

HIGH
7.5
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

Using gss-ntlmssp by gssapi?

Get instant alerts when new vulnerabilities affect gss-ntlmssp - before attackers find them.

Real-time alertsTrack your software stackFree plan available
Severity
HIGH7.5
Exploit prediction
EPSS 1%
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, multiple out-of-bounds reads when decoding NTLM fields can trigger a denial of service. A 32-bit integer overflow condition can lead to incorrect checks of consistency of length of internal buffers. Although most applications will error out before accepting a singe input buffer of 4GB in length this could theoretically happen. This vulnerability can be triggered via the main `gss_accept_sec_context` entry point if the application allows tokens greater than 4GB in length. This can lead to a large, up to 65KB, out-of-bounds read which could cause a denial-of-service if it reads from unmapped memory. Version 1.2.0 contains a patch for the out-of-bounds reads.

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
NONE
Availability
HIGH
Vector?

Quick Info

StatusMODIFIED
CWE
CWE-125

Get alerted

Stop reading CVE feeds looking for your own stack

Track the products you run and VulnTracker tells you when a new CVE affects them — with what is known about fixing it, and nothing about the rest.

Free plan, no card