CVE-2023-25565 : What You Need to Know

This CVE involves a vulnerability in GSS-NTLMSSP prior to version 1.2.0, affecting the GSSAPI library that implements NTLM authentication. An incorrect free when decoding target information can lead to a denial of service attack.

Understanding CVE-2023-25565

This vulnerability in GSS-NTLMSSP, a mechglue plugin, can be exploited to trigger a denial of service attack due to an incorrect free operation when decoding target information.

What is CVE-2023-25565?

The vulnerability in GSS-NTLMSSP version < 1.2.0 stems from an error condition where the

cb

and

sh

buffers are incorrectly assumed to contain data that needs to be freed. This misconception leads to a denial of service risk when the main

gss_accept_sec_context

entry point is called, potentially causing an assertion failure in

free

.

The Impact of CVE-2023-25565

The impact of CVE-2023-25565 is rated as HIGH with a CVSS v3.1 base score of 7.5. The attack vector is through NETWORK, and the availability impact is considered HIGH. While confidentiality and integrity impacts are deemed NONE, the severity is classified as HIGH.

Technical Details of CVE-2023-25565

This section delves into the vulnerability description, affected systems and versions, as well as the exploitation mechanism.

Vulnerability Description

The vulnerability arises from an incorrect free operation when decoding target information in GSS-NTLMSSP version < 1.2.0, leading to a denial of service risk triggered by the

gss_accept_sec_context

entry point.

Affected Systems and Versions

The affected system is the gss-ntlmssp product prior to version 1.2.0, which is vulnerable to the incorrect free operation leading to a denial of service attack.

Exploitation Mechanism

The exploitation of this vulnerability involves triggering the incorrect free operation during the decoding of target information in GSS-NTLMSSP prior to version 1.2.0, potentially leading to a denial of service through an assertion failure in

free

.

Mitigation and Prevention

To address CVE-2023-25565, immediate steps should be taken along with implementing long-term security practices and applying necessary patches and updates.

Immediate Steps to Take

Users are advised to update to version 1.2.0 of GSS-NTLMSSP to mitigate the vulnerability and prevent potential denial of service attacks stemming from the incorrect free operation.

Long-Term Security Practices

In the long term, organizations should maintain a proactive approach to security by regularly updating software, conducting security assessments, and following best practices to mitigate vulnerabilities.

Patching and Updates

It is crucial to apply patches and updates promptly to ensure systems are protected against known vulnerabilities like CVE-2023-25565. Regularly monitoring for security advisories and maintaining up-to-date software versions is essential in mitigating risks.