Zyxel Multiple Firewalls OS Command Injection Vulnerability (CVE-2023-28771)
Severity: critical · Patch status: patched · Since 2023-05-31 · CVE-2023-28771
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. CISA added CVE-2023-28771 to its Known Exploited Vulnerabilities catalog on May 31, 2023, which means attackers are exploiting it in the wild.
What to do
- Apply updates per vendor instructions.
- US federal agencies must remediate by Jun 21, 2023 (BOD 22-01); treat that as the outer limit.
Sources
All live incidents on Threat Watch