SARA / Free Tools / CVE / CVE-2017-20203

CVE-2017-20203 — NetSarang Xmanager Enterprise 5

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 special

CVSS
9.3 CRITICAL
EPSS
0.51% (top 33.90%)
CWE
CWE-506
Published
2025-10-09T17:01:08.016Z
Last modified
2025-11-21T14:17:59.011Z
CVSS vector
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

01What is this vulnerability?

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…

02Affected products

VendorProductVersions
NetSarang Computer, Inc.Xmanager Enterprise5.0 Build 1232
NetSarang Computer, Inc.Xmanager5.0 Build 1045
NetSarang Computer, Inc.Xshell5.0 Build 1322
NetSarang Computer, Inc.Xftp5.0 Build 1218
NetSarang Computer, Inc.Xlpd5.0 Build 1220

03Active exploitation status

Not currently listed on the CISA Known Exploited Vulnerabilities (KEV) catalog. EPSS is the best forward-looking signal — see the EPSS row above.

04Recommended remediation

05Technical details

For the full vendor write-up, exploit chains, and reference implementations, see the references list in section 09.

06Detection signatures

Ask SARA in chat to draft a starting detection for this CVE in your stack of choice.

07Related CVEs

No directly-cited follow-up CVEs in the KB record for this advisory. The references list in section 09 carries the vendor cross-references.

08Timeline

09References

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