SecuriTricks - CVE-2017-20203

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.

Product(s) Impacted

Vendor	Product	Versions
Netsarang	Xmanager Enterprise Xmanager Xshell Xftp Xlpd	5.0 5.0 5.0 5.0 5.0

Weaknesses

Common security weaknesses mapped to this vulnerability.

CWE-506

Embedded Malicious Code

The product contains code that appears to be malicious in nature.

*CPE(s)

Affected systems and software identified for this CVE.

Type	Vendor	Product	Version	Update	Edition	Language	Software Edition	Target Software	Target Hardware	Other Information
a	netsarang	xmanager_enterprise	5.0	1232	/	/	/	/	/	/
a	netsarang	xmanager	5.0	1045	/	/	/	/	/	/
a	netsarang	xshell	5.0	1322	/	/	/	/	/	/
a	netsarang	xftp	5.0	1218	/	/	/	/	/	/
a	netsarang	xlpd	5.0	1220	/	/	/	/	/	/
a	netsarang	xmanager_enterprise	5.0	1236	/	/	/	/	/	/
a	netsarang	xmanager	5.0	1049	/	/	/	/	/	/
a	netsarang	xshell	5.0	1326	/	/	/	/	/	/
a	netsarang	xftp	5.0	1222	/	/	/	/	/	/
a	netsarang	xlpd	5.0	1224	/	/	/	/	/	/

References

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

CVSS Score

9.3 / 10

CVSS Data - 4.0

Attack Vector: NETWORK
Attack Complexity: LOW
Attack Requirements: NONE
Privileges Required: NONE
User Interaction: ACTIVE
Scope:
Confidentiality Impact: HIGH
Integrity Impact: HIGH
Availability Impact: NONE
Exploit Maturity: NOT_DEFINED

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

View Vector String

Timeline

Published: Oct. 9, 2025, 5:15 p.m.
Last Modified: Oct. 9, 2025, 5:15 p.m.

Status : Received

CVE has been recently published to the CVE List and has been received by the NVD.

More info

Source

disclosure@vulncheck.com

CVE-2017-20203