Headline
CVE-2023-25566: Memory leak when parsing usernames
GSS-NTLMSSP is a mechglue plugin for the GSSAPI library that implements NTLM authentication. Prior to version 1.2.0, a memory leak can be triggered when parsing usernames which can trigger a denial-of-service. The domain portion of a username may be overridden causing an allocated memory area the size of the domain name to be leaked. An attacker can leak memory via the main gss_accept_sec_context entry point, potentially causing a denial-of-service. This issue is fixed in version 1.2.0.
Summary
A memory leak can be triggered when parsing usernames which can trigger a denial-of-service.
Details
The domain portion of a username may be overridden causing an allocated memory area the size of the domain name to be leaked.
Impact
An attacker can leak memory can leak memory via the main gss_accept_sec_context entry point, potentially causing a denial-of-service.
Related news
Red Hat Security Advisory 2023-3097-01 - The gssntlmssp is a GSSAPI NTLM mechanism that allows to perform NTLM authentication in GSSAPI programs. Issues addressed include memory leak and out of bounds read vulnerabilities.
An update for gssntlmssp is now available for Red Hat Enterprise Linux 8. Red Hat Product Security has rated this update as having a security impact of Moderate. A Common Vulnerability Scoring System (CVSS) base score, which gives a detailed severity rating, is available for each vulnerability from the CVE link(s) in the References section.This content is licensed under the Creative Commons Attribution 4.0 International License (https://creativecommons.org/licenses/by/4.0/). If you distribute this content, or a modified version of it, you must provide attribution to Red Hat Inc. and provide a link to the original. Related CVEs: * CVE-2023-25563: A flaw was found in GSS-NTLMSSP, a mechglue plugin for the GSSAPI library that implements NTLM authentication. Multiple out-of-bounds reads occur when decoding NTLM fields and can trigger a denial of service. A 32-bit integer overflow condition can lead to incorrect checks of the consistency of the length of internal buffers. Although most app...
GSS-NTLMSSP is a mechglue plugin for the GSSAPI library that implements NTLM authentication. Prior to version 1.2.0, an incorrect free when decoding target information can trigger a denial of service. The error condition incorrectly assumes the `cb` and `sh` buffers contain a copy of the data that needs to be freed. However, that is not the case. This vulnerability can be triggered via the main `gss_accept_sec_context` entry point. This will likely trigger an assertion failure in `free`, causing a denial-of-service. This issue is fixed in version 1.2.0.