CVE-2017-20203
NetSarang v5.0 Malicious Backdoor Supply Chain Compromise
- Published
- Updated
- Reserved
- Assigned by
- VulnCheck
Description
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.
Scores
| Scored by | CVSS | Score | Vector |
|---|---|---|---|
| VulnCheckCNA (assigner) | 4.0 | Critical9.3 | CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:H/VI:H/VA:N/SC:H/SI:H/SA:N |
| NVDNVD · Deferred | 4.0 | Critical9.3 | CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:H/VI:H/VA:N/SC:H/SI:H/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X |
- EPSS (exploitation in 30 days)
- 0.67% · top 48% of all CVEs (4 Nov 2026)
- CISA SSVC
- Exploitation: none · Automatable: yes · Technical impact: total
The list uses the assigner's score when there is one, then CISA's, then NVD's: Critical 9.3.
Weakness
Affected products
NetSarang Computer, Inc. · Xmanager Enterprise
- affected 5.0 Build 1232
NetSarang Computer, Inc. · Xmanager
- affected 5.0 Build 1045
NetSarang Computer, Inc. · Xshell
- affected 5.0 Build 1322
NetSarang Computer, Inc. · Xftp
- affected 5.0 Build 1218
NetSarang Computer, Inc. · Xlpd
- affected 5.0 Build 1220
References (4)
- https://web.archive.org/web/20181022035109/https://www.netsarang.com/news/security_exploit_in_july_18_2017_build.html (opens in a new tab)vendor-advisorypatch
- https://usa.kaspersky.com/about/press-releases/shadowpad-attackers-hid-backdoor-in-software-used-by-hundreds-of-large-companies-worldwide (opens in a new tab)technical-description
- https://securelist.com/shadowpad-in-corporate-networks/81432/ (opens in a new tab)technical-description
- https://www.vulncheck.com/advisories/netsarang-malicious-backdoor-supply-chain-compromise (opens in a new tab)third-party-advisory
Sources
The same CVE in the primary databases and aggregators, to check against.
- CVE.org record (opens in a new tab)
- CVE List JSON (GitHub) (opens in a new tab)
- NVD (opens in a new tab)
- FIRST EPSS (opens in a new tab)
- OSV.dev (opens in a new tab)
- GitHub Advisories (opens in a new tab)
- CIRCL Vulnerability-Lookup (opens in a new tab)
Badge for a README or a ticket
[](https://trackcve.app/cve/CVE-2017-20203)Record last updated .