Security readout for executives and security teams
This is a critical remote command execution flaw in Zyxel firewall firmware. An attacker does not need credentials or user interaction; crafted network packets can trigger operating system command execution on affected devices. Because firewalls sit at the network edge, compromise can threaten confidentiality, integrity, availability, and internal network trust. Exposure is likely where affected Zyxel firewall families run the listed firmware ranges, particularly internet-facing perimeter or VPN devices. The source bundle does not identify all deployment modes, fixed versions, or whether every configuration is reachable by the vulnerable packet path. Treat this as an emergency perimeter-device issue. The combination of unauthenticated remote command execution, critical CVSS score, firewall placement, and CISA KEV listing creates high business urgency for rapid inventory, patching, and compromise assessment. Mitigation focus: Inventory Zyxel ZyWALL/USG, VPN, USG FLEX, and ATP firewall firmware versions.; Apply Zyxel vendor firmware updates or remediation guidance for this advisory.; Prioritize internet-facing and remote-access firewall appliances first..
Michael Williams reviewed this cited source version on .
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CWE-78: Command execution behavior lookup
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Open ATT&CK lookupCVE-2023-28771 mapping review
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Open ATT&CK lookup- Severity
- Critical
- CVSS
- 9.8 (3.1)
- Known Exploited
- Yes
- Published
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
CNA and ADP enrichment extracted from CVE v5
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CISA KEV status
CVSS vector scores
1 official scoreWe collect every scored CVSS vector available in the official CNA and ADP containers. When more than one version is present, the table keeps the source vectors side by side instead of collapsing them into the highest score.
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H3.95.9Primary CVE scoreVulnerability scoring details
Base CVSS 3.1 score
9.8CriticalVector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Source materials
- CVE List V5 sourceCVE List V5
- https://www.zyxel.com/global/en/support/security-advisories/zyxel-security-advisory-for-remote-command-injection-vulnerability-of-firewallsCVE reference
- https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2023-28771CVE reference · government-resource
Products and packages named in the record
CWE details
CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.
Improper Neutralization of Special Elements used in an OS Command ('OS Command Injection')
Improper Neutralization of Special Elements used in an OS Command ('OS Command Injection') represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.