CVE-2018-13383
Published: January 10, 2022
Official Description
A heap buffer overflow in Fortinet FortiOS and FortiProxy may cause the SSL VPN web service termination for logged in users.
CISA KEV Advisory
Fortinet FortiOS and FortiProxy Out-of-bounds Write
A heap buffer overflow in Fortinet FortiOS and FortiProxy may cause the SSL VPN web service termination for logged in users.
Apply updates per vendor instructions.
Risk Analysis
This is a high-severity heap buffer overflow in Fortinet FortiOS and FortiProxy that can cause the SSL VPN web service to terminate for logged-in users, resulting in a denial of service. Despite a low EPSS score of 0.01315, its inclusion in CISA's KEV catalog confirms it has been actively exploited.
This vulnerability has been actively exploited in the wild. It is remotely exploitable, affecting the SSL VPN web service.
Apply the latest security updates for Fortinet FortiOS and FortiProxy to address this buffer overflow. Monitor SSL VPN services for unusual activity and ensure proper resource allocation.
Technical Analysis
CVE-2018-13383 requires local access, meaning attackers must already have a foothold on the target system.
Exploitation requires some privileges, which limits the exposure to scenarios where an attacker has already gained initial access.
CISA has added CVE-2018-13383 to the Known Exploited Vulnerabilities (KEV) catalog, confirming active exploitation in the wild. U.S. federal agencies are required to patch this within the mandated timeframe, and all organizations should treat remediation as urgent.
Affected Vendors & Products
Exploit & PoC Resources
All References (1)
Quick Facts
Recommended Actions
- →Apply vendor patches immediately
- →Monitor CVE-2018-13383 in threat intel feeds
- →Review IDS/IPS signatures for exploitation attempts
- !CISA KEV: Federal agencies must patch per BOD 22-01 timeline
- !Active exploitation confirmed — treat as P1