Experts Warn of Attacks on a Cisco ASA Security Flaw due to a new Proof-of-Concept Exploit

RedSeal Cyber Threat Series            

Researchers at Positive Technologies have created a proof-of-concept (PoC) exploit that leverages a 2020 Cisco ASA vulnerability. A Cisco administrator would have to click on a link that takes the unsuspecting user to a web page where the malware is downloaded and the Cisco ASA must not be patched. Cisco released a patch for a Medium Severity web services vulnerability that affects the Cisco Adaptive Security Appliance (ASA) Software and Cisco Firepower Threat Defense (FTD) Software CVE-2020-3580. This security flaw can allow an unauthenticated attacker to remotely conduct a cross site scripting (XSS) attack against a user of the web services interface.

Enterprises should patch their Cisco ASA Software and Firepower Software as soon as possible.  A successful attack could allow the attacker to execute code or access sensitive browser information.   

RedSeal customers should:

  1. Run a custom best practice check to receive a list of vulnerable devices
  2. Create and run daily reports until all affected systems are patched.

For additional details, contact your RedSeal sales representatives or email

Cybersecurity Best Practices 

  • Keep your devices patched and up to date 
  • Ensure you are using TLS v1.2 or above; disable lower versions of TLS and HTTP 
  • Disable WebVPN or AnyConnect if not in use on your device