CVE-2017-20203
Essential information
- Published
- 09/10/2025 17:15
- Modified
- 09/10/2025 17:15
- Author
- —
- Creator
- —
- CVSS
- 9.3 CRITICAL (v3) 9.3 CRITICAL (v4.0)
- CISA KEV
- No
- CWE
- —
- CVSS vector
-
—
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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
CVSS metrics
- Access vector
- —
- Access complexity
- —
- Authentication
- —
- Confidentiality impact
- —
- Integrity impact
- —
- Availability impact
- —
- Exploitability
- —
- Remediation level
- —
- Report confidence
- —
- Temporal score
- —
- Attack vector
- —
- Attack complexity
- —
- Privileges required
- —
- User interaction
- —
- Scope
- —
- Confidentiality impact
- —
- Integrity impact
- —
- Availability impact
- —
- Exploit code maturity
- —
- Remediation level
- —
- Report confidence
- —
- Temporal score
- —
- Attack vector
- NETWORK
- Attack complexity
- LOW
- Attack requirements
- NONE
- Privileges required
- NONE
- User interaction
- ACTIVE
- Confidentiality (V)
- HIGH
- Confidentiality (S)
- HIGH
- Integrity (V)
- HIGH
- Integrity (S)
- HIGH
- Availability (V)
- NONE
- Availability (S)
- NONE
- Exploit maturity
- NOT_DEFINED
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.
NVD status
- Status
- Received — CVE has been recently published to the CVE List and has been received by the NVD.
- Source
- [email protected]
- NVD
- View on NVD
Affected products (CPE)
| Product | CPE |
|---|---|
| netsarang / xmanager enterprise | cpe:2.3:a:netsarang:xmanager_enterprise:5.0:1232:*:*:*:*:*:* |
| netsarang / xmanager | cpe:2.3:a:netsarang:xmanager:5.0:1045:*:*:*:*:*:* |
| netsarang / xshell | cpe:2.3:a:netsarang:xshell:5.0:1322:*:*:*:*:*:* |
| netsarang / xftp | cpe:2.3:a:netsarang:xftp:5.0:1218:*:*:*:*:*:* |
| netsarang / xlpd | cpe:2.3:a:netsarang:xlpd:5.0:1220:*:*:*:*:*:* |
| netsarang / xmanager enterprise | cpe:2.3:a:netsarang:xmanager_enterprise:5.0:1236:*:*:*:*:*:* |
| netsarang / xmanager | cpe:2.3:a:netsarang:xmanager:5.0:1049:*:*:*:*:*:* |
| netsarang / xshell | cpe:2.3:a:netsarang:xshell:5.0:1326:*:*:*:*:*:* |
| netsarang / xftp | cpe:2.3:a:netsarang:xftp:5.0:1222:*:*:*:*:*:* |
| netsarang / xlpd | cpe:2.3:a:netsarang:xlpd:5.0:1224:*:*:*:*:*:* |