Cyber Resilience

CVE-2021-22123

RCE in Fortinet Fortiweb 5.9.0 – 6.2.4

High EPSSRCECommand Injection
Published
01 June 2021
Modified
21 November 2024
Patch / advisory
View advisory
CVSS Score v3.1 7.6
Click a component to see what it means
Raw vectorCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:H
EPSS Score 0.77 99.5th percentile
Risk Priority 80 floored blend · peak EPSS

Summary

CVE-2021-22123 is a high-severity OS Command Injection (CWE-78) vulnerability in Fortinet Fortiweb. Its CVSS base score is 7.6 (High).

Operationally, ranked in the top 0.5% of CVEs by exploit likelihood; it is not currently listed in the CISA KEV catalog.

OWASP Top 10 for Web (2025)

A05:2025 Injection

EU & UK References

Vulnerability Data

An OS command injection vulnerability in FortiWeb's management interface 6.3.7 and below, 6.2.3 and below, 6.1.x, 6.0.x, 5.9.x may allow a remote authenticated attacker to execute arbitrary commands on the system via the SAML server configuration page.

CWE(s)
CWE-78

Related Threats

Likely ATT&CK TechniquesAI

Techniques this vulnerability likely enables, inferred from its description, weakness type, and attributed-actor tradecraft. Confidence is per-technique.

T1190 Exploit Public-Facing Application Initial Accessconfidence: HIGH
OS command injection in the management interface allows remote authenticated attackers to execute arbitrary commands.
attack.mitre.org →
T1059.004 Unix Shell Executionconfidence: HIGH
The vulnerability enables execution of arbitrary OS commands via the Unix shell on the FortiWeb appliance.
attack.mitre.org →
inferred from description + CWE · MITRE ATT&CK Enterprise v19.0

CVEs Like This One

CVE-2023-23779Same product: Fortinet Fortiweb
CVE-2024-50569Same product: Fortinet Fortiweb
CVE-2025-66178Same product: Fortinet Fortiweb
CVE-2023-23777Same product: Fortinet Fortiweb
CVE-2024-50567Same product: Fortinet Fortiweb
CVE-2025-58034Same product: Fortinet Fortiweb
CVE-2025-27759Same product: Fortinet Fortiweb
CVE-2025-47857Same product: Fortinet Fortiweb
CVE-2025-53609Same product: Fortinet Fortiweb
CVE-2026-40688Same product: Fortinet Fortiweb

Affected Assets

fortinet
fortiweb
5.9.0 — 6.2.4 · 6.3.0 — 6.3.8

Mitigating Controls

Control response

Prevent
Stop it (NIST 800-53)

—

Detect
Catch it (NIST detect / respond)

—

Harden
Shrink the surface (DISA STIG)

—

Validate
Prove the fix (OWASP ASVS)
  • V1.2.5
  • V1.2.8
  • V15.2.5

Likely Mitigating Controls AI

Per-CVE control mapping for this CVE has not run yet; the list below is derived from the weakness types (CWEs) cited in the NVD entry.

SC-27 Platform-independent Applications
addresses: CWE-78

Platform-independent apps typically execute inside a managed runtime or sandbox that restricts direct OS command execution, reducing the ability to exploit OS command injection.

SI-10 Information Input Validation
addresses: CWE-78

Validates inputs to block special elements that would alter OS command execution.

Mitigating Controls (NIST CSF 2.0) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→CSF cross-walk (authority under review) — links open the control.

PR.PS-06 mostly match
prevents

PR.PS-06's SDLC practices directly require secure coding and input handling that blocks command-injection defects, yet the single broad outcome leaves many specific neutralization vectors and verification gaps unaddressed.

PR.PS-02 partial match
prevents

Routine patching/maintenance can remediate known command-injection CVEs in dependencies (partial forward) but does nothing to stop developers from introducing improper neutralization in custom code (none reverse).

Mitigating Controls (ISO/IEC 27001:2022 Annex A) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→ISO cross-walk (authority under review) — links open the control.

A.8.29 Security testing in development and acceptance mostly match
detects

Security testing and code review target insecure use of operating-system command interfaces, catching command-injection flaws introduced during development.

References