Stack-based buffer overflow in Fortinet FortiFone
Priority LOW 35CWE-121Published · Updated
Key facts
- Attack vector
- Network
- Privileges required
- High
- User interaction
- None
- Attack complexity
- Low
- Impact type
- Code execution
- Confidentiality · integrity · availability
- High · High · High
- Fix status
- No fix listed
Attack profile from CVSS 3.1 · NVD. Fix status from CNA. Impact type from CWE-121 and the CVSS impact.
Summary
Multiple stack-based buffer overflows in the command line interpreter of FortiWeb before 6.4.2 may allow an authenticated attacker to achieve arbitrary code execution via specially crafted commands.
Why it matters now
Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.00816 57th percentileScored 2026-11-07
Fix No fix listed No fixed version in the sources yet
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- None
- Automatable
- No
- Technical impact
- Total
The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| Fortinet | FortiFone | 3.0.0 – 3.0.11 | — | No fix listed | CNA |
| Fortinet | FortiADC | 7.0.0; 6.2.0 – 6.2.2; 6.1.0 – 6.1.6; 6.0.0 – 6.0.4; 5.4.0 – 5.4.5; 5.3.0 – 5.3.7; 5.2.0 – 5.2.8; 5.1.0 – 5.1.7; 5.0.0 – 5.0.4 | — | No fix listed | CNA |
| Fortinet | FortiMail | 7.0.0 – 7.0.2; 6.4.0 – 6.4.6; 6.2.0 – 6.2.8; 6.0.0 – 6.0.12; 5.4.0 – 5.4.12 | — | No fix listed | CNA |
| Fortinet | FortiDDoS | 5.7.0; 5.6.0 – 5.6.1; 5.5.0 – 5.5.1; 5.4.0 – 5.4.3; 5.3.0 – 5.3.2; 5.2.0; 5.1.0; 5.0.0; 4.7.0; 4.6.0; 4.5.0; 4.4.0 – 4.4.2 | — | No fix listed | CNA |
| Fortinet | FortiDDoS-F | 6.3.0; 6.2.0 – 6.2.2; 6.1.0 – 6.1.4 | — | No fix listed | CNA |
| Fortinet | FortiVoice | 6.4.0 – 6.4.4; 6.0.0 – 6.0.10 | — | No fix listed | CNA |
| Fortinet | FortiDDoS-CM | 5.5.0 – 5.5.1; 5.4.0 – 5.4.3; 5.3.0 – 5.3.1; 5.2.0; 5.1.0; 5.0.0; 4.7.0 | — | No fix listed | CNA |
| Fortinet | FortiWeb | 6.4.0 – 6.4.1; 6.3.0 – 6.3.15 | — | No fix listed | CNA |
| Fortinet | FortiRecorder | 6.4.0 – 6.4.2; 6.0.0 – 6.0.10; 2.7.0 – 2.7.7; 2.6.0 – 2.6.3 | — | No fix listed | CNA |
| Fortinet | FortiNDR | 1.5.0 – 1.5.3; 1.4.0; 1.3.0 – 1.3.1; 1.2.0; 1.1.0 | — | No fix listed | CNA |
- FortiFone VendorFortinet Affected 3.0.0 – 3.0.11 Fixed in — No fix listed CNA
- FortiADC VendorFortinet Affected 7.0.0; 6.2.0 – 6.2.2; 6.1.0 – 6.1.6; 6.0.0 – 6.0.4; 5.4.0 – 5.4.5; 5.3.0 – 5.3.7; 5.2.0 – 5.2.8; 5.1.0 – 5.1.7; 5.0.0 – 5.0.4 Fixed in — No fix listed CNA
- FortiMail VendorFortinet Affected 7.0.0 – 7.0.2; 6.4.0 – 6.4.6; 6.2.0 – 6.2.8; 6.0.0 – 6.0.12; 5.4.0 – 5.4.12 Fixed in — No fix listed CNA
- FortiDDoS VendorFortinet Affected 5.7.0; 5.6.0 – 5.6.1; 5.5.0 – 5.5.1; 5.4.0 – 5.4.3; 5.3.0 – 5.3.2; 5.2.0; 5.1.0; 5.0.0; 4.7.0; 4.6.0; 4.5.0; 4.4.0 – 4.4.2 Fixed in — No fix listed CNA
- FortiDDoS-F VendorFortinet Affected 6.3.0; 6.2.0 – 6.2.2; 6.1.0 – 6.1.4 Fixed in — No fix listed CNA
- FortiVoice VendorFortinet Affected 6.4.0 – 6.4.4; 6.0.0 – 6.0.10 Fixed in — No fix listed CNA
- FortiDDoS-CM VendorFortinet Affected 5.5.0 – 5.5.1; 5.4.0 – 5.4.3; 5.3.0 – 5.3.1; 5.2.0; 5.1.0; 5.0.0; 4.7.0 Fixed in — No fix listed CNA
- FortiWeb VendorFortinet Affected 6.4.0 – 6.4.1; 6.3.0 – 6.3.15 Fixed in — No fix listed CNA
- FortiRecorder VendorFortinet Affected 6.4.0 – 6.4.2; 6.0.0 – 6.0.10; 2.7.0 – 2.7.7; 2.6.0 – 2.6.3 Fixed in — No fix listed CNA
- FortiNDR VendorFortinet Affected 1.5.0 – 1.5.3; 1.4.0; 1.3.0 – 1.3.1; 1.2.0; 1.1.0 Fixed in — No fix listed CNA
CPE configurations NVD · 1
| CPE | Versions | Role | Vendor |
|---|---|---|---|
| cpe:2.3:a:fortinet:fortiweb:*:*:*:*:*:*:*:* | 5.0.0 to before 6.2.6; 6.3.0 to before 6.3.16; 6.4.0 to before 6.4.2 | Vulnerable | Fortinet |
- cpe:2.3:a:fortinet:fortiweb:*:*:*:*:*:*:*:* Versions 5.0.0 to before 6.2.6; 6.3.0 to before 6.3.16; 6.4.0 to before 6.4.2 Vulnerable ·Fortinet
Remediation
No fixed version listed by the sources yet.
Timeline
- 2026-10-02 Threatist record created from CVE-2021-36193
- 2026-10-03 Alias added: GHSA-xfch-762x-q3v9
References
More Fortinet Fortiweb vulnerabilities
- TI-2026-20057 Authentication bypass in Fortinet FortiWeb KEVCVSS 3.1CRITICAL 9.4
- TI-2025-39856 Path traversal in Fortinet FortiWeb KEVCVSS 3.1CRITICAL 9.4
- TI-2025-18919 SQL injection in Fortinet FortiWeb KEVCVSS 3.1CRITICAL 9.8
- TI-2025-35886 OS command injection in Fortinet FortiWeb KEVCVSS 3.1MEDIUM 6.7
- TI-2021-05113 OS command injection in Fortinet FortiWeb CVSS 3.1HIGH 8.8
- TI-2021-18960 Stack-based buffer overflow in Fortinet FortiWeb CVSS 3.1CRITICAL 9.8
Sources
- CVE-2021-36193 · CVE Program
- CVE-2021-36193 · NVD
- FIRST EPSS
- GHSA-xfch-762x-q3v9 · GitHub Advisory Database · CC BY 4.0
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences