The Digester

Amazon says Interlock exploited critical Cisco firewall bug weeks before patch

Mar 18th 2026

Amazon security chief says Interlock exploited a maximum severity Cisco Secure Firewall Management Center bug starting January 26, 36 days before public disclosure, and Cisco issued fixes on March 4.

  • Amazon CISO CJ Moses says Interlock exploited CVE-2026-20131 beginning January 26, 36 days before the vulnerability was publicly disclosed
  • The flaw allowed an unauthenticated remote attacker to execute arbitrary Java code as root on Cisco Secure Firewall Management Center
  • Cisco released fixes on March 4 and said it will update its advisory to reflect active exploitation
  • Amazon detected the activity in its MadPot honeypot and found a misconfigured server exposing Interlock's toolkit
  • Interlock's toolkit harvests extensive host and browser data, compresses per-host ZIPs, and uses custom RATs and implants for persistent access
  • The group deploys redundant implants including a Java GlassFish backdoor, memory-only Java classes, Bash reverse proxy scripts, and legitimate remote access tools to blend in
  • Amazon attributed the activity to Interlock using artifacts such as an ELF binary, an embedded ransom note, and a TOR negotiation portal, and noted the group has previously hit hospitals and the city of Saint Paul