CVE-2017-20203

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.

• CWE-506

• https://securelist.com/shadowpad-in-corporate-networks/81432/
• https://usa.kaspersky.com/about/press-releases/shadowpad-attackers-hid-backdoor-in-software-used-by-hundreds-of-large-companies-worldwide
• https://web.archive.org/web/20181022035109/https://www.netsarang.com/news/security_exploit_in_july_18_2017_build.html
• https://www.vulncheck.com/advisories/netsarang-malicious-backdoor-supply-chain-compromise

Published

Oct 9, 2025

Last Modified

Jun 17, 2026

Status

Deferred

• How Strix found a critical auth bypass in etcdStrix autonomously discovered a critical authentication bypass in etcd, later designated CVE-2026-33413.
• Autonomous PentestingAI agents that find and validate exploitable vulnerabilities like this one across your applications.
• PR ReviewsPentest every pull request so vulnerable code is caught before it ships to production.
• AI Penetration TestingHow AI-driven penetration testing continuously covers your attack surface.

• CVE-2017-20198The Marathon UI in DC/OS < 1.9.0 allows unauthenticated user…9.3
• CVE-2017-20199A vulnerability was found in Buttercup buttercup-browser-ext…6.5
• CVE-2017-2020Rejected reason: DO NOT USE THIS CANDIDATE NUMBER. ConsultI…
• CVE-2017-20200A vulnerability has been found in Coinomi up to 1.7.6. This …3.7
• CVE-2017-20201CCleaner v5.33.6162 and CCleaner Cloud v1.07.3191 (32-bit bu…9.3
• CVE-2017-20202Web Developer for Chrome v0.4.9 contained malicious code tha…9.3
• CVE-2017-20204DBLTek GoIP devices (models GoIP 1, 4, 8, 16, and 32) contai…9.3
• CVE-2017-20205Valve's Source SDK (source-sdk-2013)'s ragdoll model parsing…9.2
• CVE-2017-20206The Appointments plugin for WordPress is vulnerable to PHP O…9.8
• CVE-2017-20207The Flickr Gallery plugin for WordPress is vulnerable to PHP…9.8
• CVE-2017-20208The RegistrationMagic – Custom Registration Forms, User Regi…9.8
• CVE-2017-20209Nagios Fusion versions prior to 4.0.1 are vulnerable to cros…6.1