Exploited vulnerability · CISA KEV

Is CVE-2023-27997 exploited? Yes: in CISA KEV since 13 Jun 2023

Gociux · Fortinet FortiOS and FortiProxy SSL-VPN · data: CISA KEV, CVE record, FIRST EPSS

Yes. CVE-2023-27997, Fortinet FortiOS and FortiProxy SSL-VPN Heap-Based Buffer Overflow Vulnerability, is being exploited in the wild. CISA added it to its Known Exploited Vulnerabilities catalog on 13 Jun 2023, the day it was published. It is known to be used in ransomware campaigns. It affects Fortinet FortiOS and FortiProxy SSL-VPN, an internet-facing product of the kind attackers use for initial access. If you run it, CISA's required action is: Apply updates per vendor instructions.

What it is

Fortinet FortiOS and FortiProxy SSL-VPN contain a heap-based buffer overflow vulnerability which can allow an unauthenticated, remote attacker to execute code or commands via specifically crafted requests.

What to do

1. Check whether you run it. Look for FortiOS and FortiProxy SSL-VPN in your asset inventory, including appliances and cloud images. Stack check lists every exploited Fortinet CVE at once.
2. Apply the fix. Apply updates per vendor instructions.
3. If you can't patch today, take the affected service off the internet or restrict who can reach it, and check its logs for signs of compromise since 13 Jun 2023.
4. Get told next time. Email alerts when CISA adds a CVE for Fortinet.

References

• www.fortiguard.com/psirt/FG-IR-23-097
• nvd.nist.gov/vuln/detail/CVE-2023-27997

Sources: CISA KEV (exploitation, ransomware use, required action, due date), the CVE record (publication date, CVSS, CNA), NVD and FIRST EPSS (live score). More: all KEV additions in June 2023 · Fortinet scorecard · act-now radar.