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BREACH BRIEF🟠 High Advisory

CISA Orders Federal Agencies to Hunt for Persistent Cisco “Firestarter” Backdoor

CISA and the U.K. NCSC have identified a custom backdoor, dubbed “Firestarter,” embedded in Cisco ASA and Firepower appliances on a federal network. The implant survives reboots and patches, giving attackers remote code execution and persistent control, prompting an urgent hunt across all federal agencies and raising supply‑chain concerns for any organization using the same hardware.

LiveThreat™ Intelligence · 📅 April 25, 2026· 📰 databreachtoday.com
🟠
Severity
High
AD
Type
Advisory
🎯
Confidence
High
🏢
Affected
2 sector(s)
Actions
4 recommended
📰
Source
databreachtoday.com

CISA Orders Federal Agencies to Hunt for Persistent Cisco “Firestarter” Backdoor

What Happened – CISA and the U.K. NCSC disclosed a previously unknown, persistent backdoor (“Firestarter”) embedded in Cisco Adaptive Security Appliance (ASA) and Firepower devices on a federal civilian network. The implant can survive reboots, firmware upgrades and standard patching, giving attackers remote code execution within core system processes.

Why It Matters for TPRM

  • The backdoor leverages two Cisco‑published CVEs (CVE‑2025‑20333, CVE‑2025‑20362) that were already mandated for remediation, yet infection persists after patching.
  • Federal‑level supply‑chain compromise signals a high likelihood of similar exposure in private‑sector organizations that run identical Cisco hardware.
  • Persistent implants that survive normal hardening undermine traditional vulnerability‑management controls, requiring deeper forensic and continuous‑monitoring capabilities.

Who Is Affected – Government agencies, contractors, and any enterprise that deploys Cisco ASA/Firepower perimeter devices (e.g., telecom, finance, healthcare, cloud providers).

Recommended Actions

  • Inventory all Cisco ASA and Firepower appliances; verify firmware versions and patch status.
  • Conduct a dedicated “Firestarter” hunt using CISA‑provided IOC signatures and network‑traffic baselines.
  • Collect system artifacts (memory dumps, config files) for forensic analysis.
  • Review third‑party risk contracts for clauses covering supply‑chain malware and ensure vendors can provide evidence of remediation.

Technical Notes – The implant is delivered via a shellcode loader previously tracked as “Line Viper” and then establishes persistence through a custom backdoor. It exploits CVE‑2025‑20333 (remote code execution) and CVE‑2025‑20362 (privilege escalation). The backdoor survives reboots and firmware upgrades, rendering standard patch cycles insufficient. Source: DataBreachToday

📰 Original Source
https://www.databreachtoday.com/cisa-hunts-for-cisco-backdoor-spotted-on-federal-network-a-31505

This LiveThreat Intelligence Brief is an independent analysis. Read the original reporting at the link above.

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