CVE-2023-6398

Severity: high (CVSS 7.2 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 1.3% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2024-02-20 · updated 2026-06-17
Weakness: CWE-78

Description

A post-authentication command injection vulnerability in the file upload binary 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, USG FLEX H series firmware versions from 1.10 through 1.10 Patch 1, NWA50AX firmware versions through 6.29(ABYW.3), WAC500 firmware versions through 6.65(ABVS.1), WAX300H firmware versions through 6.60(ACHF.1), and WBE660S firmware versions through 6.65(ACGG.1) could allow an authenticated attacker with administrator privileges to execute some operating system (OS) commands on an affected device via FTP.

Affected products

Zyxel Atp100 Firmware: from 4.32 before 5.37; 5.37, 5.37-patch1 — fixed in 5.37
Zyxel Atp100W Firmware: from 4.32 before 5.37; 5.37, 5.37-patch1 — fixed in 5.37
Zyxel Atp200 Firmware: from 4.32 before 5.37; 5.37, 5.37-patch1 — fixed in 5.37
Zyxel Atp500 Firmware: from 4.32 before 5.37; 5.37, 5.37-patch1 — fixed in 5.37
Zyxel Atp700 Firmware: from 4.32 before 5.37; 5.37, 5.37-patch1 — fixed in 5.37
Zyxel Atp800 Firmware: from 4.32 before 5.37; 5.37, 5.37-patch1 — fixed in 5.37
Zyxel NWA110AX firmware: before 6.70\(abtg.2\) — fixed in 6.70\(abtg.2\)
Zyxel NWA1123ACv3 firmware: before 6.70\(abvt.1\) — fixed in 6.70\(abvt.1\)
Zyxel Nwa210Ax Firmware: before 6.70\(abtd.2\) — fixed in 6.70\(abtd.2\)
Zyxel Nwa220Ax-6E Firmware: before 6.70\(acco.1\) — fixed in 6.70\(acco.1\)
Zyxel Nwa50Ax-Pro Firmware: before 6.80\(acge.0\) — fixed in 6.80\(acge.0\)
Zyxel NWA50AX firmware: before 6.29\(abyw.4\) — fixed in 6.29\(abyw.4\)
Zyxel Nwa55Axe Firmware: before 6.29\(abzl.4\) — fixed in 6.29\(abzl.4\)
Zyxel Nwa90Ax-Pro Firmware: before 6.80\(acgf.0\) — fixed in 6.80\(acgf.0\)
Zyxel Nwa90Ax Firmware: before 6.29\(accv.4\) — fixed in 6.29\(accv.4\)
Zyxel USG FLEX H series uOS firmware: 1.10, 1.10-patch1
Zyxel Usg20-Vpn Firmware: from 4.16 before 5.37; 5.37, 5.37-patch1 — fixed in 5.37
Zyxel USG20(W)-VPN firmware: from 4.16 before 5.37; 5.37, 5.37-patch1 — fixed in 5.37
Zyxel firewall (ZLD): from 4.50 before 5.37; 5.37, 5.37-patch1 — fixed in 5.37
Zyxel Usg Flex 100Ax Firmware: from 4.50 before 5.37; 5.37, 5.37-patch1 — fixed in 5.37
Zyxel Usg Flex 100H Firmware: from 4.50 before 5.37; 5.37, 5.37-patch1 — fixed in 5.37
Zyxel USG FLEX 100(W) firmware: from 4.50 before 5.37; 5.37, 5.37-patch1 — fixed in 5.37
Zyxel USG FLEX 200 firmware: from 4.50 before 5.37; 5.37, 5.37-patch1 — fixed in 5.37
Zyxel Usg Flex 200H Firmware: from 4.50 before 5.37; 5.37, 5.37-patch1 — fixed in 5.37
Zyxel Usg Flex 200Hp Firmware: from 4.50 before 5.37; 5.37, 5.37-patch1 — fixed in 5.37
Zyxel USG FLEX 500 firmware: from 4.50 before 5.37; 5.37, 5.37-patch1 — fixed in 5.37
Zyxel Usg Flex 500H Firmware: from 4.50 before 5.37; 5.37, 5.37-patch1 — fixed in 5.37
Zyxel Usg Flex 50 Firmware: from 4.16 before 5.37; 5.37, 5.37-patch1 — fixed in 5.37
Zyxel USG FLEX 50(W) firmware: from 4.16 before 5.37; 5.37, 5.37-patch1 — fixed in 5.37
Zyxel USG FLEX 700 firmware: from 4.50 before 5.37; 5.37, 5.37-patch1 — fixed in 5.37

How to fix

Upgrade to a fixed version: Zyxel Atp100 Firmware 5.37; Zyxel Atp100W Firmware 5.37; Zyxel Atp200 Firmware 5.37; Zyxel Atp500 Firmware 5.37; Zyxel Atp700 Firmware 5.37; Zyxel Atp800 Firmware 5.37; Zyxel NWA110AX firmware 6.70\(abtg.2\); Zyxel NWA1123ACv3 firmware 6.70\(abvt.1\); Zyxel Nwa210Ax Firmware 6.70\(abtd.2\); Zyxel Nwa220Ax-6E Firmware 6.70\(acco.1\); Zyxel Nwa50Ax-Pro Firmware 6.80\(acge.0\); Zyxel NWA50AX firmware 6.29\(abyw.4\). Check the vendor advisory for mitigations.

References

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