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CVE-2017-20203

NetSarang v5.0 Malicious Backdoor Supply Chain Compromise

Published
Last modified
published
Not listed in CISA KEV
Fix
Fix or patch referenced
None on Exploit-DB, Metasploit or GitHub
  • Exploitation: none
  • Automatable: yes
  • Technical impact: total

Summary

NetSarang Xmanager Enterprise 5.0 Build 1232, Xmanager 5.0 Build 1045, Xshell 5.0 Build 1322, Xftp 5.0 Build 1218, and Xlpd 5.0 Build 1220 contain a malicious nssock2.dll that implements a multi-stage, DNS-based backdoor. The dormant library contacts a C2 DNS server via a specially crafted TXT record for a month‑generated domain. After receiving a decryption key, it then downloads and executes arbitrary code, creates an encrypted virtual file system (VFS) in the registry, and grants the attacker full remote code execution, data exfiltration, and persistence. NetSarang released builds for each product line that remediated the compromise: Xmanager Enterprise Build 1236, Xmanager Build 1049, Xshell Build 1326, Xftp Build 1222, and Xlpd Build 1224. Kaspersky Lab identified an instance of exploitation in the wild in August 2017.

Timeline

  1. CVE published
  2. CISA SSVC assessment

    Exploitation: none · Automatable: yes · Technical impact: total

  3. Record last updated

Affected versions

  • NetSarang Computer, Inc. Xmanager Enterprise

    5.0 Build 1232

  • NetSarang Computer, Inc. Xmanager

    5.0 Build 1045

  • NetSarang Computer, Inc. Xshell

    5.0 Build 1322

  • NetSarang Computer, Inc. Xftp

    5.0 Build 1218

  • NetSarang Computer, Inc. Xlpd

    5.0 Build 1220

References 4

web.archive.org

usa.kaspersky.com

securelist.com

vulncheck.com