On Friday, January 22, SonicWall released a statement about a vulnerability in its own product being exploited, NetExtender VPN Client and Secure Mobile Access. However, after lots of research and testing, SonicWall has confirmed that NetExtender is not affected and only certain versions of Secure Mobile Access contain this vulnerability.
The linked statement above contains specific information about corrective action you can take now to protect your network from these types of attacks. At this point firewalls do not appear to be affected.
For organizations that do have the affected versions of Secure Mobile Access, SonicWall urges you to enable multi-factor authentication on all accounts and to configure whitelist access.