{"cve":"CVE-2023-27991","nvd":{"published":"2023-04-24T18:15:09.497","modified":"2026-06-17T05:46:19.873","status":"Modified","description":"The post-authentication command injection vulnerability in the CLI command of Zyxel ATP series firmware versions 4.32 through 5.35, USG FLEX series firmware versions 4.50 through 5.35, USG FLEX 50(W) firmware versions 4.16 through 5.35, USG20(W)-VPN firmware versions 4.16 through 5.35, and VPN series firmware versions 4.30 through 5.35, which could allow an authenticated attacker to execute some OS commands remotely.","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","score":8.8},"cwes":["CWE-78"],"references":["https://www.zyxel.com/global/en/support/security-advisories/zyxel-security-advisory-for-xss-vulnerability-and-post-authentication-command-injection-vulnerability-in-firewalls","https://www.zyxel.com/global/en/support/security-advisories/zyxel-security-advisory-for-xss-vulnerability-and-post-authentication-command-injection-vulnerability-in-firewalls"],"products":["zyxel:atp100_firmware","zyxel:atp100w_firmware","zyxel:atp200_firmware","zyxel:atp500_firmware","zyxel:atp700_firmware","zyxel:atp800_firmware","zyxel:usg20-vpn_firmware","zyxel:usg_20w-vpn_firmware","zyxel:usg_flex_100_firmware","zyxel:usg_flex_100w_firmware","zyxel:usg_flex_200_firmware","zyxel:usg_flex_500_firmware","zyxel:usg_flex_50_firmware","zyxel:usg_flex_50w_firmware","zyxel:usg_flex_700_firmware","zyxel:vpn1000_firmware","zyxel:vpn100_firmware","zyxel:vpn300_firmware","zyxel:vpn50_firmware"],"source":"nvd","synced_at":"2026-10-19T21:38:05.473481323+00:00"},"epss":{"cve":"CVE-2023-27991","score":0.01453,"percentile":0.73426,"date":"2026-10-31"},"kev":null,"osv":[],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}