336,000 servers remain unpatched against critical Fortigate vulnerability

Researchers say that nearly 336,000 devices exposed to the Internet remain vulnerable to a critical vulnerability in firewalls sold by Fortinet because admins have yet to install patches the company released three weeks ago.

CVE-2023-27997 is a remote code execution in Fortigate VPNs, which are included in the company’s firewalls. The vulnerability, which stems from a heap overflow bug, has a severity rating of 9.8 out of 10. Fortinet released updates silently patching the flaw on June 8 and disclosed it four days later in an advisory that said it may have been exploited in targeted attacks. That same day, the US Cybersecurity and Infrastructure Security Administration added it to its catalog of known exploited vulnerabilities and gave federal agencies until Tuesday to patch it.

Despite the severity and the availability of a patch, admins have been slow to fix it, researchers said. Security firm Bishop Fox on Friday, citing data retrieved from queries of the Shodan search engine, said that of 489,337 affected devices exposed on the internet, 335,923 of them—or 69 percent—remained unpatched. Bishop Fox said that some of the vulnerable machines appeared to be running Fortigate software that hadn’t been updated since 2015.