CVE-2023-27997
Fortinet FortiOS and FortiProxy SSL-VPN Heap-Based Buffer Overflow Vulnerability
MITRE ATT&CK techniques
How this vulnerability maps to adversary behaviour, from the Center for Threat-Informed Defense's public CVE→ATT&CK mappings. Use it to check whether your detections already cover the technique.
Summary
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.
Affected software
Vendor: Fortinet · Product: FortiOS and FortiProxy SSL-VPN
Weakness types (CWE):
What to do
This vulnerability appears in CISA's Known Exploited Vulnerabilities catalog, meaning it is being exploited in the wild. Prioritize patching affected systems and verify exposure across your estate.
Related vulnerabilities in Fortinet
| CVE | Name | EPSS | Exploited |
|---|---|---|---|
| CVE-2018-13379 | Fortinet FortiOS SSL VPN Path Traversal Vulnerability | 100.0% | Yes |
| CVE-2022-40684 | Fortinet Multiple Products Authentication Bypass Vulnerability | 100.0% | Yes |
| CVE-2022-42475 | Fortinet FortiOS Heap-Based Buffer Overflow Vulnerability | 99.5% | Yes |
| CVE-2024-55591 | Fortinet FortiOS and FortiProxy Authentication Bypass Vulnerability | 98.3% | Yes |
| CVE-2023-48788 | Fortinet FortiClient EMS SQL Injection Vulnerability | 97.6% | Yes |
| CVE-2025-25257 | Fortinet FortiWeb SQL Injection Vulnerability | 96.7% | Yes |
| CVE-2024-47575 | Fortinet FortiManager Missing Authentication Vulnerability | 94.8% | Yes |
| CVE-2026-21643 | Fortinet FortiClient EMS SQL Injection Vulnerability | 94.1% | Yes |
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