We have researched the exploitation claim in first post of the topic.
We can find no basis for this claim “Exploitation of this vulnerability will allow full access to the router device.” Following these instructions will NOT allow access/control of the router and will NOT allow further efforts to enable access/control of the router.
By following the instruction for the first "sshd heap corruption”, the sshd service of the router will exit and will not restart. This is a denial of service as only a reboot of the router will make the ssh remote management service available again.
The second method that causes a crash of the sshd program also provides a denial of service as the sshd does not restart and the router requires a reboot to have sshd available. It does not allow or make it possible for further efforts to gain access/control of the router.
To protect yourself from the denial of sshd service (so that you can always use ssh):
- For those users that do not wish to upgrade:
For home users that use the default firewall configuration (comes preset), there is no reason to upgrade as the default firewall does not allow access to management interfaces from the interface connected to the internet.
For network administrators that do allow ssh access to the router, it is advised to add firewall rules to restrict access to trusted ports or disable ssh management.
- For users that would like to upgrade:
RouterOS v6.3 and v5.26 has already fixed this issue.
As always, the security of RouterOS is our main concern, and we continue to research bug reports.