CVE-2023-33009
CISA KEVPublished June 5, 2023 · Updated April 3, 2026
high
Official Description+
Zyxel ATP, USG FLEX, USG FLEX 50(W), USG20(W)-VPN, VPN, and ZyWALL/USG firewalls contain a buffer overflow vulnerability in the notification function that could allow an unauthenticated attacker to cause denial-of-service (DoS) conditions and remote code execution on an affected device.
Affected Products
| Vendor | Product |
|---|---|
| Zyxel | Multiple Firewalls |
Patch Status
Patch by 2023-06-26
Recommended Actions
- Check if your systems use any of the affected products listed above.
- Apply vendor patches immediately if available.
- This vulnerability is in CISA's Known Exploited Vulnerabilities catalog — prioritize remediation.
- Monitor vendor advisories for updates and additional mitigations.
- Review logs for indicators of compromise related to CVE-2023-33009.