All vulnerabilities
CVE-2023-28771

Zyxel Multiple Firewalls OS Command Injection Vulnerability

Zyxel Multiple FirewallsNetwork & edge
Open in ThreatlineRecord JSON
CVSS
9.8Critical
ExploitationExploited in the wildAdded to KEV 31 May 2023CISA KEV
Exploit odds (EPSS)99.3%Chance of exploitation activity in the next 30 days, higher than 99.9% of CVEs. Scored 23 Oct 2026FIRST EPSS
Fixed inNone listedNo source names a fixed version. Check the vendor advisory below
Federal deadline21 Jun 2023Remediation due date for US federal agenciesCISA KEV
CISA required actionApply updates per vendor instructions. CISA KEV

What fixes it

No source in this snapshot names a fixed version. The vendor advisories under References are the place to check.

Timeline

  1. 31 Mar 2023Exploit code publicMetasploit
  2. 25 Apr 2023, 00:00 UTCPublishedCVE List
  3. 31 May 2023Added to CISA KEVCISA KEV

Public exploit code and templates 1

  • Exploit moduleZyxel IKE Packet Decoder Unauthenticated Remote Code Execution 31 Mar 2023Metasploit

Listed so defenders can prioritize. Threatline links to the source and does not host exploit code.

Description

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.

Text from CVE List

Affected versions 4

  • ZyWALL/USG series firmwareaffected: 4.60 through 4.73CVE List
  • VPN series firmwareaffected: 4.60 through 5.35CVE List
  • USG FLEX series firmwareaffected: 4.60 through 5.35CVE List
  • ATP series firmwareaffected: 4.60 through 5.35CVE List

References 3