[Update] Vulnerability in Fortinet FortiOS (February 9, 2024)
Actively exploited. At least one CVE in this advisory is listed in the CISA Known Exploited Vulnerabilities catalog — exploitation has been observed in the wild. Treat remediation as urgent.
[Update on March 19, 2024] CERT-FR is aware of public exploit codes and new exploitation attempts. On February 8, 2024, Fortinet published the security advisory regarding the critical vulnerability CVE-2024-21762 affecting FortiOS SSL VPN. This vulnerability...
CSIRTS triage
- What
- A critical vulnerability affects FortiOS SSL VPN, with public exploit codes and new exploitation attempts reported.
- Who is affected
- Deployments of Fortinet FortiOS are affected.
- Urgency
- Remediation is urgent due to active exploitation and critical severity.
- Action
- Apply the security updates released by Fortinet.
AI-assisted analysis generated from the source advisory — verify against the original.
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Details
Original advisory: https://www.cert.ssi.gouv.fr/alerte/CERTFR-2024-ALE-004/
Exploitation outlook
EPSS (FIRST.org) estimates each CVE’s probability of exploitation in the next 30 days — here is the CSIRTS.com read on those numbers.
- Exploitation confirmedCVE-2024-21762Already exploited in the wild (CISA KEV) — the prediction phase is over. Patch now. Riskier than 100% of all scored CVEs.
Referenced CVEs
| CVE | CSIRTS overview | External |
|---|---|---|
| CVE-2024-21762 | coverage & exploitation status | NVD · CVE.org |
Same CVEs, other sources
How other CERTs, PSIRTs and databases cover the vulnerabilities in this advisory.
- unknownPost-exploitation activities in Fortinet FortiGate (April 11, 2025)cert-fr-alerte
- criticalexploitedCVE-2024-21762: Fortinet FortiOS Out-of-Bound Write Vulnerabilitycisa-kev
Recent advisories for Fortinet FortiOS
A cluster of recent advisories against the same product widens the attack surface — attackers routinely chain freshly published CVEs on one product, so review these together.
- criticalexploitedCVE-2019-6693: Fortinet FortiOS Use of Hard-Coded Credentials Vulnerabilitycisa-kev · 2025-06-25
- criticalexploitedCVE-2025-24472: Fortinet FortiOS and FortiProxy Authentication Bypass Vulnerabilitycisa-kev · 2025-03-18
- criticalexploitedCVE-2024-55591: Fortinet FortiOS and FortiProxy Authentication Bypass Vulnerabilitycisa-kev · 2025-01-14
- criticalexploitedCVE-2024-21762: Fortinet FortiOS Out-of-Bound Write Vulnerabilitycisa-kev · 2024-02-09
- criticalexploitedCVE-2023-27997: Fortinet FortiOS and FortiProxy SSL-VPN Heap-Based Buffer Overflow Vulnerabilitycisa-kev · 2023-06-13
- criticalexploitedCVE-2022-41328: Fortinet FortiOS Path Traversal Vulnerabilitycisa-kev · 2023-03-14
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