CVE-2023-2283 : Security Advisory and Response

This article provides detailed information about CVE-2023-2283, a vulnerability found in libssh affecting the authentication check of connecting clients.

Understanding CVE-2023-2283

CVE-2023-2283 is a vulnerability discovered in libssh, where the authentication check of the connecting client can be bypassed in the

pki_verify_data_signature

function due to memory allocation problems.

What is CVE-2023-2283?

The vulnerability in libssh arises from an issue where insufficient memory or limited memory usage can lead to bypassing the authentication check of the connecting client. This occurs due to the initialization of the return value

rc

to SSH_ERROR, which is then rewritten to store the return value of the function call

pki_key_check_hash_compatible

. The variable's value remains unchanged between these points, potentially allowing errors to call

goto error

and return SSH_OK during cryptographic verification.

The Impact of CVE-2023-2283

Exploitation of CVE-2023-2283 could enable unauthorized access to systems utilizing affected versions of libssh. Attackers may bypass authentication checks, leading to potential security breaches and unauthorized access to sensitive information.

Technical Details of CVE-2023-2283

The following technical aspects are crucial to understanding the CVE-2023-2283 vulnerability in libssh:

Vulnerability Description

The vulnerability in libssh stems from memory allocation issues that allow the authentication check of connecting clients to be bypassed, posing a significant security risk.

Affected Systems and Versions

The vulnerability affects the

libssh-2

version, making systems utilizing this specific version susceptible to bypassing the authentication check.

Exploitation Mechanism

Exploiting CVE-2023-2283 involves leveraging memory allocation problems to manipulate the

pki_verify_data_signature

function and bypass the authentication check of connecting clients.

Mitigation and Prevention

It is crucial to take immediate steps to mitigate the risks associated with CVE-2023-2283 and prevent potential security breaches.

Immediate Steps to Take

Update libssh to a patched version that addresses the vulnerability.
Monitor network activity for any signs of unauthorized access or malicious behavior.
Implement access controls and authentication mechanisms to enhance system security.

Long-Term Security Practices

Regularly update software and apply security patches to mitigate known vulnerabilities.
Conduct security assessments and audits to identify and address weaknesses in the system.
Educate users and administrators about security best practices to prevent exploitation of vulnerabilities.

Patching and Updates

Ensure that you stay informed about security updates and patches released by libssh to address CVE-2023-2283. Promptly apply these updates to secure your systems against potential risks.