Risk Letters

Exploited vulnerability

CVE-2023-28771

TLP:CLEAR

Zyxel Multiple Firewalls OS Command Injection Vulnerability

Zyxel ATP, USG FLEX, VPN, and ZyWALL/USG firewalls allow for improper error message handling which could allow an unauthenticated attacker to execute OS commands remotely by sending crafted packets to an affected device.

Facts

  • Vendor: Zyxel
  • Product: Multiple Firewalls
  • CVSS: 9.8
  • EPSS (probability of exploitation within 30 days): 99.3 %
  • On CISA's Known Exploited Vulnerabilities list since: 31 May 2023
  • First known exploitation: 31 May 2023
  • CISA's deadline for US federal agencies: 21 June 2023
  • Weakness: CWE-78
  • First seen by Risk Letters: 31 May 2023

Members see which Nordic sectors the flaw hits, and what to do about it.

Get the full brief

Data: NVD (public domain), CISA KEV, FIRST EPSS, MITRE ATT&CK, AlienVault OTX. NVD