CVE-2017-20203
NetSarang v5.0 Malicious Backdoor Supply Chain Compromise
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.
INFO
Published Date :
Oct. 9, 2025, 5:15 p.m.
Last Modified :
Oct. 14, 2025, 7:37 p.m.
Remotely Exploit :
Yes !
Source :
[email protected]
Affected Products
The following products are affected by CVE-2017-20203
vulnerability.
Even if cvefeed.io is aware of the exact versions of the
products
that
are
affected, the information is not represented in the table below.
No affected product recoded yet
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS 4.0 | CRITICAL | 83251b91-4cc7-4094-a5c7-464a1b83ea10 | ||||
| CVSS 4.0 | CRITICAL | [email protected] |
Solution
- Update Xmanager Enterprise to Build 1236.
- Update Xmanager to Build 1049.
- Update Xshell to Build 1326.
- Update Xftp to Build 1222.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2017-20203.
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2017-20203 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2017-20203
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2017-20203 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2017-20203 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
-
New CVE Received by [email protected]
Oct. 09, 2025
Action Type Old Value New Value Added 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. Added CVSS V4.0 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 Added CWE CWE-506 Added Reference https://securelist.com/shadowpad-in-corporate-networks/81432/ Added Reference https://usa.kaspersky.com/about/press-releases/shadowpad-attackers-hid-backdoor-in-software-used-by-hundreds-of-large-companies-worldwide Added Reference https://web.archive.org/web/20181022035109/https://www.netsarang.com/news/security_exploit_in_july_18_2017_build.html Added Reference https://www.vulncheck.com/advisories/netsarang-malicious-backdoor-supply-chain-compromise