Raw vector
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:HCVSS and EPSS are reproduced from their sources (NVD, FIRST EPSS). Risk Priority is our own derived reading, not an NVD score.
Summary
CVE-2023-22913 is a high-severity Command Injection (CWE-77) vulnerability in Zyxel Usg Flex 100 Firmware. Its CVSS base score is 8.1 (High).
Operationally, ranked in the top 30% of CVEs by exploit likelihood; it is not currently listed in the CISA KEV catalog.
OWASP Top 10 for Web (2025)
EU & UK References
- 🇪🇺 ENISA EUVD: EUVD-2023-27015
Vulnerability Data
A post-authentication command injection vulnerability in the “account_operator.cgi” CGI program of Zyxel USG FLEX series firmware versions 4.50 through 5.35, and VPN series firmware versions 4.30 through 5.35, which could allow a remote authenticated attacker to modify device configuration data,…
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resulting in denial-of-service (DoS) conditions on an affected device.
- CWE(s)
Related Threats
CVEs Like This One
Affected Assets
Mitigating Controls
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.8.25 mandates secure SDLC practices including secure coding guidelines, security requirements, checkpoints, testing (scans/penetration), and developer training that reduce command injection defects, but leaves a minority slice (e.g. incomplete implementation of those practices, outsourced development without full assurance, or post-SDLC changes) where the weakness can still arise and be exploitable.
Application security requirements explicitly call for controls against injection flaws including command injection.
A.8.27 mandates security-by-design principles (e.g. distrust external input, secure session control, data validation/sanitization, least privilege) and design reviews that can stop command injection from being introduced, but this is only a minority slice of CWE-77 because the weakness can still arise in code that bypasses those principles, in non-reviewed components, or in runtime injection vectors the architecture review does not reach.
Secure coding standards require proper escaping and parameterization of commands, directly eliminating CWE-77.
Security testing in development catches command-injection vulnerabilities before release.
Hardening callouts derived
DISA STIG baselines are authored against specific weaknesses. Where this CVE cites a broad weakness class, the mapping is not asserted at that abstraction (owner ruling, 2026-09-25: grade only at Base and below), so no rule is shown here rather than a rule shown against the wrong grain.
- No fine-grained STIG row for CWE-77, a class-level weakness, and none of its children carries one either.