An improper authentication vulnerability in SSL VPN in FortiOS 6.4.0, 6.2.0 to 6.2.3, 6.0.9 and below may result in a user being able to log in successfully without being prompted for the second factor of authentication (FortiToken) if they changed the case of their username.
Published: 2021-04-08
Threat actors and ransomware groups are actively targeting three legacy Fortinet vulnerabilities. Background On April 2, the Federal Bureau of Investigation (FBI) along with the Cybersecurity and Infrastructure Security Agency (CISA) issued a joint cybersecurity advisory regarding activity involving advanced persistent threat (APT) actors.
https://www.cisa.gov/news-events/cybersecurity-advisories/aa23-352a
https://duo.com/decipher/hive-ransomware-attacks-target-fortios-microsoft-exchange-flaws
https://www.tenable.com/cyber-exposure/a-look-inside-the-ransomware-ecosystem
https://www.tenable.com/cyber-exposure/2021-threat-landscape-retrospective
https://www.tenable.com/blog/hold-the-door-why-organizations-need-to-prioritize-patching-ssl-vpns
https://www.cisa.gov/news-events/cybersecurity-advisories/aa21-209a