Out-of-bounds Read in Gssapi Gss-Ntlmssp
CVE-2023-25563
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.
Vulnerability class: Buffer Overflow
EPSS: 0.011 (63.2th percentile) — read the EPSS interpretation.
CVSS v3 metric
CVSS v3 base score 5.9 (Medium). Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H.
Affected products
- Gssapi Gss-ntlmssp — versions < 1.2.0
- Gss-ntlmssp_project Gss-ntlmssp
Weakness classification (CWE)
Public proof-of-concept exploits
References
- security-advisories@github.com (x_refsource_CONFIRM, Third Party Advisory)
- security-advisories@github.com (Patch, Third Party Advisory, x_refsource_MISC)
- security-advisories@github.com (Third Party Advisory, x_refsource_MISC)
Frequently asked questions
- What is CVE-2023-25563?
- CVE-2023-25563 is a medium-severity vulnerability in Gssapi Gss-Ntlmssp, classified under Out-of-bounds Read. CVSS score: 5.9/10. Published 2023-02-14.
- How severe is CVE-2023-25563?
- Medium severity. CVSS v3 base score is 5.9 out of 10.
- Is CVE-2023-25563 known to be exploited?
- 1 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.