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Vulnerability record · CVE-2017-17023 · published 9 April 2019

CVE-2017-17023: Ncp-e ncp secure entry client insufficient verification of data authenticity vulnerability

NNcp E · Ncp Secure Entry Client

The Sophos UTM VPN endpoint interacts with client software provided by NPC Engineering (www.ncp-e.com). The affected client software, "Sophos IPSec Client" 11.04 is a rebranded version of NCP "Secure Entry Client" 10.11 r32792. A vulnerability in the software update feature of the VPN client allows a man-in-the-middle (MITM) or man-on-the-side (MOTS) attacker to execute arbitrary, malicious software on a target user's computer. This is related to SIC_V11.04-64.exe (Sophos), NCP_EntryCl_Windows_x86_1004_31799.exe (NCP), and ncpmon.exe (both Sophos and NCP). The vulnerability exists because: (1) the VPN client requests update metadata over an insecure HTTP connection; and (2) the client software does not check if the software update is signed before running it.

8.1 CVSS 3.0 High EPSS 0.61% · top 52.8% CWE-345 · Insufficient verification of data authenticity
8.1CVSS 3.0 base score, v2 9.3
0.61%EPSS exploitation probability, 30 days
NoNot in CISA KEV
2Affected product versions listed by NVD
4References
17 Jun 2026Last modified by NVD

Description

The Sophos UTM VPN endpoint interacts with client software provided by NPC Engineering (www.ncp-e.com). The affected client software, "Sophos IPSec Client" 11.04 is a rebranded version of NCP "Secure Entry Client" 10.11 r32792. A vulnerability in the software update feature of the VPN client allows a man-in-the-middle (MITM) or man-on-the-side (MOTS) attacker to execute arbitrary, malicious software on a target user's computer. This is related to SIC_V11.04-64.exe (Sophos), NCP_EntryCl_Windows_x86_1004_31799.exe (NCP), and ncpmon.exe (both Sophos and NCP). The vulnerability exists because: (1) the VPN client requests update metadata over an insecure HTTP connection; and (2) the client software does not check if the software update is signed before running it.

CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H

Affected products

2 vulnerable configurations from NVD's CPE data, grouped by vendor and product.

References

LinkTags
https://www.ncp-e.com/en/resources/download-vpn-client/#c8680 Vendor Advisory
https://www.ncp-e.com/fileadmin/pdf/service_support/release_notes/NCP_Secure_Clients/NCP_Secure_Entry_Client/NCP_RN_Win_ Vendor Advisory
https://www.ncp-e.com/en/resources/download-vpn-client/#c8680 Vendor Advisory
https://www.ncp-e.com/fileadmin/pdf/service_support/release_notes/NCP_Secure_Clients/NCP_Secure_Entry_Client/NCP_RN_Win_ Vendor Advisory

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Related vulnerabilities

Same products first, then exploited flaws of the same weakness class.

9.8CVE-2025-26155Ncp-e ncp secure entry client untrusted search path vulnerabilityNCP Secure Enterprise Client 13.18 and NCP Secure Entry Windows Client 13.19 have an Untrusted Search Path vulnerability.EPSS 0.57%7.8CVE-2023-38831WinRAR ZIP archive spoofing leads to arbitrary code executionWinRAR before 6.23 mishandles ZIP archives that contain a benign file and a folder with the same name, causing the folder's contents to be processed …KEVEPSS 100%analysed9.8CVE-2022-26871Trend Micro Apex Central unauthenticated arbitrary file uploadTrend Micro Apex Central (and Apex One) contains an arbitrary file upload flaw caused by insufficient verification of data authenticity (CWE-345). An…KEVEPSS 19%analysed

Source: NIST National Vulnerability Database (record CVE-2017-17023), CISA KEV, FIRST EPSS (scores of 2026-09-29). This page is refreshed as NVD updates the record.