A vulnerability in the Pulse Connect Secure < 9.1R9 admin web interface could allow an authenticated attacker to perform an arbitrary code execution using uncontrolled gzip extraction.
https://www.tenable.com/cyber-exposure/a-look-inside-the-ransomware-ecosystem
https://www.tenable.com/cyber-exposure/2021-threat-landscape-retrospective
https://kb.pulsesecure.net/articles/Pulse_Security_Advisories/SA44601