{"cve":"CVE-2023-27990","nvd":{"published":"2023-04-24T18:15:09.440","modified":"2026-06-17T05:46:19.730","status":"Modified","description":"The cross-site scripting (XSS) vulnerability in 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 with administrator privileges to store malicious scripts in a vulnerable device. A successful XSS attack could then result in the stored malicious scripts being executed when the user visits the Logs page of the GUI on the device.","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:H/UI:R/S:C/C:L/I:L/A:N","score":4.8},"cwes":["CWE-79"],"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-2023-27990","score":0.00341,"percentile":0.27651,"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."]}