CVE-2023-33010
A buffer overflow vulnerability in the ID processing function in Zyxel ATP series firmware versions 4.32 through 5.36 Patch 1, USG FLEX series…
Browse: All 2023 CVEs · All vendors
- CVSS score
- 9.8 Critical
- CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H- CISA KEV
- Yes — actively exploited (added 2023-06-05, remediation due 2023-06-26)
- Weakness (CWE)
- CWE-120
- Published
- 2023-05-24
- Last modified
- 2026-06-17
- NVD status
- Analyzed
Description
A buffer overflow vulnerability in the ID processing function in Zyxel ATP series firmware versions 4.32 through 5.36 Patch 1, USG FLEX series firmware versions 4.50 through 5.36 Patch 1, USG FLEX 50(W) firmware versions 4.25 through 5.36 Patch 1, USG20(W)-VPN firmware versions 4.25 through 5.36 Patch 1, VPN series firmware versions 4.30 through 5.36 Patch 1, ZyWALL/USG series firmware versions 4.25 through 4.73 Patch 1, could allow an unauthenticated attacker to cause denial-of-service (DoS) conditions and even a remote code execution on an affected device.
Affected products
- zyxel atp100 firmware
- zyxel atp200 firmware
- zyxel atp500 firmware
- zyxel atp100w firmware
- zyxel atp700 firmware
- zyxel atp800 firmware
- zyxel usg flex 100 firmware
- zyxel usg flex 50 firmware
- zyxel usg flex 200 firmware
- zyxel usg flex 500 firmware
- zyxel usg flex 700 firmware
- zyxel usg flex 100w firmware
Affected ranges per NVD CPE data; confirm exact versions in the vendor advisory.
Required action (CISA)
Apply updates per vendor instructions. Federal remediation deadline: 2023-06-26.
How to prioritize this
This vulnerability is on the CISA KEV list, meaning it is being actively exploited — treat it as urgent regardless of the raw CVSS number. Use the live CVE lookup for the latest NVD data, and the CVSS 3.1 calculator to model your own environmental score. For the actively exploited vulnerabilities that matter this week, read The Exploit HQ daily security brief.
References
- https://www.zyxel.com/global/en/support/security-advisories/zyxel-security-advisory-for-multiple-buffer-overflow-vulnerabilities-of-firewalls
- https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2023-33010
FAQ
Is CVE-2023-33010 actively exploited?
Yes. CISA added CVE-2023-33010 to its Known Exploited Vulnerabilities (KEV) catalog on 2023-06-05, with a federal remediation deadline of 2023-06-26. A KEV listing means real-world exploitation is confirmed, so patching this should be prioritized above many higher-CVSS bugs that aren't being exploited.
What is the CVSS score of CVE-2023-33010?
CVE-2023-33010 has a CVSS base score of 9.8 (Critical). Its vector string is CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H.
Related vulnerabilities
- CVE-2024-11667 — Zyxel Multiple Firewalls
- CVE-2023-33009 — Zyxel Multiple Firewalls
- CVE-2023-28771 — Zyxel Multiple Firewalls
- CVE-2022-30525 — Zyxel Multiple Firewalls
- CVE-2026-7273 — Zyxel GS1900 Series Switches
- CVE-2024-40891 — Zyxel DSL CPE Devices
Data source: NVD & CISA KEV. Shown as-is; nothing added. Last generated from NVD data — re-check the live tool for updates.
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