{"cve":"CVE-2023-6399","nvd":{"published":"2024-02-20T02:15:49.407","modified":"2026-06-17T06:50:41.280","status":"Analyzed","description":"A format string vulnerability in Zyxel ATP series firmware versions from 4.32 through 5.37 Patch 1, USG FLEX series firmware versions from 4.50 through 5.37 Patch 1, USG FLEX 50(W) series firmware versions from 4.16 through 5.37 Patch 1, USG20(W)-VPN series firmware versions from 4.16 through 5.37 Patch 1, and USG FLEX H series firmware versions from 1.10 through 1.10 Patch 1 could allow an authenticated IPSec VPN user to cause DoS conditions against the “deviceid” daemon by sending a crafted hostname to an affected device if it has the “Device Insight” feature enabled.","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H","score":6.5},"cwes":["CWE-134"],"references":["https://www.zyxel.com/global/en/support/security-advisories/zyxel-security-advisory-for-multiple-vulnerabilities-in-firewalls-and-aps-02-20-2024","https://www.zyxel.com/global/en/support/security-advisories/zyxel-security-advisory-for-multiple-vulnerabilities-in-firewalls-and-aps-02-20-2024"],"products":["zyxel:atp100_firmware","zyxel:atp100w_firmware","zyxel:atp200_firmware","zyxel:atp500_firmware","zyxel:atp700_firmware","zyxel:atp800_firmware","zyxel:uos","zyxel:usg20-vpn_firmware","zyxel:usg20w-vpn_firmware","zyxel:usg_flex_100_firmware","zyxel:usg_flex_100ax_firmware","zyxel:usg_flex_100h_firmware","zyxel:usg_flex_100w_firmware","zyxel:usg_flex_200_firmware","zyxel:usg_flex_200h_firmware","zyxel:usg_flex_200hp_firmware","zyxel:usg_flex_500_firmware","zyxel:usg_flex_500h_firmware","zyxel:usg_flex_50_firmware","zyxel:usg_flex_50w_firmware","zyxel:usg_flex_700_firmware","zyxel:usg_flex_700h_firmware"],"source":"nvd","synced_at":"2026-10-19T21:45:59.823092188+00:00"},"epss":{"cve":"CVE-2023-6399","score":0.00649,"percentile":0.51111,"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."]}