Fortinet · FortiOS and FortiProxy SSL-VPN
CVE-2023-27997
Fortinet FortiOS and FortiProxy SSL-VPN Heap-Based Buffer Overflow Vulnerability
What it is
A heap-based buffer overflow vulnerability [CWE-122] in FortiOS version 7.2.4 and below, version 7.0.11 and below, version 6.4.12 and below, version 6.0.16 and below and FortiProxy version 7.2.3 and below, version 7.0.9 and below, version 2.0.12 and below, version 1.2 all versions, version 1.1 all versions SSL-VPN may allow a remote attacker to execute arbitrary code or commands via specifically crafted requests.
CISA: 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
Apply updates per vendor instructions.
Deadline for US federal agencies: July 4, 2023
- Added to the CISA list
- June 13, 2023
- Published
- June 13, 2023
- Severity
- Critical 9.2 CVSS 3.1
- Chance of attacks in the next 30 days (EPSS)
- 86% in the top 0.3% of all known vulnerabilities
- Weakness
- CWE-122
- More details
- NVD · CVE.org · CISA
All references (1)
More exploited flaws from Fortinet
| Added | Vulnerability | Product | Severity | Attack chance |
|---|---|---|---|---|
| Oct 16, 2026 | Path Traversal | Multiple Products | Medium 5.4 | 1.3% |
| Oct 1, 2026 | Path Traversal | FortiMail | Critical 9.8 | 4.6% |
| Sep 9, 2026 | Heap-based Buffer Overflow | Multiple Products | High 7.4 | 3.7% |
| Jul 27, 2026 | Exposure of Sensitive Information to an Unauthorized Actor | FortiOS | Medium 5.3 | 29% |
| Jul 16, 2026 | OS Command Injection | FortiSandbox | Critical 9.1 | 76% |
| Jul 16, 2026 | OS Command Injection | FortiSandbox | Critical 9.1 | 93% |
| Apr 13, 2026 | SQL Injection | FortiClient EMS | Critical 9.1 | 98% |
| Apr 6, 2026 | Improper Access Control | FortiClient EMS | Critical 9.1 | 94% |
Sources: Known Exploited Vulnerabilities (CISA, public domain), CVE records (cve.org) and EPSS (FIRST). The chance of attacks is the EPSS estimate that someone will try to exploit the flaw in the next 30 days.