This article provides information on how to mitigate the CVE-2024-6387 vulnerability.

→ Applies to: SynetoOS 4.x

Vulnerability description

The vulnerability, identified in the OpenSSH server, enables remote unauthenticated attackers to execute arbitrary code on the target server, presenting a severe risk to systems that utilize OpenSSH for secure communications. 

SOURCES
Vulcan (https://vulcan.io/blog/cve-2024-6387-how-to-fix-regresshion-vulnerability)

Solution

Update to the latest OpenSSH version, restrict SSH access to trusted networks, use key-based authentication, and monitor logs for unusual activity.

As a temporary fix, if updating is not feasible, set LoginGraceTime to 0.
 

Step 1. Connect to SynetoOS appliance via SSH as admin

ssh admin@<your_ip_address_or_hostname>

Step 2 (optional). Change into Solaris shell (in case you're directed to an unsupported shell)

un sh

Step 3. Get root privileges

sudo su -

Step 4. Update the SSH server config file

sed -i 's/^#\?\s*LoginGraceTime\s\+.*/LoginGraceTime 0/' /etc/ssh/sshd_config

Step 5. Restart the SSH server

svcadm restart svc:/network/ssh:default

Step 6. Check that the SSH service is online

svcs svc:/network/ssh:default