Fortinet FortiOS and FortiProxy Out-of-bounds Write

[ Why it matters ]Priority signals

• Exploited in the wild: on CISA's Known Exploited Vulnerabilities list since 2022-01-10
• Known to be used in ransomware campaigns
• EPSS: 34% chance of exploitation in the next 30 days (higher than 98% of CVEs)

[ Description ]Official description

A heap buffer overflow in Fortinet FortiOS 6.0.0 through 6.0.4, 5.6.0 through 5.6.10, 5.4.0 through 5.4.12, 5.2.14 and earlier and FortiProxy 2.0.0, 1.2.8 and earlier in the SSL VPN web portal may cause the SSL VPN web service termination for logged in users due to a failure to properly handle javascript href data when proxying webpages.

CISA: A heap buffer overflow in Fortinet FortiOS and FortiProxy may cause the SSL VPN web service termination for logged in users.

[ Fixes ]Fixes and patches

CISA required action (US federal deadline 10 Jul 2022): Apply updates per vendor instructions.

No fix or interim patch is linked from our sources yet. Check the vendor references below and limit exposure of affected systems until a fix is available.

[ References ]References

• fortiguard.com/advisory/FG-IR-18-388MitigationVendor Advisory
• fortiguard.com/advisory/FG-IR-20-229Vendor Advisory
• www.cisa.gov/known-exploited-vulnerabilities-catalogUS Government Resource