Actively exploited · Published Apr 25, 2023 · Assigned by Zyxel
CVE-2023-28771
Critical 9.8 Exploited
In plain English
A critical-severity OS command injection in ATP series firmware from Zyxel. Attackers are actively exploiting it in the wild (listed by CISA on May 31, 2023). The chance it is exploited in the next 30 days is estimated at 99.3% (higher than 99.9% of all known vulnerabilities). Ready-made attack tooling exists: Metasploit, public proof-of-concept code. Apply updates per vendor instructions.
CISA guidance
Apply updates per vendor instructions.
Federal agencies must remediate by Jun 21, 2023.
Official description
Improper error message handling in Zyxel ZyWALL/USG series firmware versions 4.60 through 4.73, VPN series firmware versions 4.60 through 5.35, USG FLEX series firmware versions 4.60 through 5.35, and ATP series firmware versions 4.60 through 5.35, which could allow an unauthenticated attacker to execute some OS commands remotely by sending crafted packets to an affected device.
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| Zyxel | ZyWALL/USG series firmware | 4.60 through 4.73 |
| Zyxel | VPN series firmware | 4.60 through 5.35 |
| Zyxel | USG FLEX series firmware | 4.60 through 5.35 |
| Zyxel | ATP series firmware | 4.60 through 5.35 |
Weakness: CWE-78 · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
References
- https://www.zyxel.com/global/en/support/security-advisories/zyxel-security-advisory-for-remote-command-injection-vulnerability-of-firewalls
- http://packetstormsecurity.com/files/172820/Zyxel-IKE-Packet-Decoder-Unauthenticated-Remote-Code-Execution.html
- https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2023-28771 government-resource