How severe is CVE-2017-17023?

CVE-2017-17023 has a CVSS 3.x base score of 8.1, rated high severity. It is exploitable over network with high attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.

Is CVE-2017-17023 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (45th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2017-17023?

CVE-2017-17023 primarily affects Ncp-e Ncp Secure Entry Client. In total, 2 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2017-17023?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.

When was CVE-2017-17023 published?

CVE-2017-17023 was published on 2019-04-09 and last updated on 2026-06-17.

CVE-2017-17023

CVE-2017-17023 is a high-severity vulnerability in Ncp-e Ncp Secure Entry Client with a CVSS 3.x base score of 8.1. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-345.

Key facts

Severity: High (CVSS 3.x base score 8.1)
CVSS v2: 9.3
EPSS exploit prediction: 1% (45th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-345
Affected product: Ncp-e Ncp Secure Entry Client
Published: 2019-04-09
Last modified: 2026-06-17

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.

Frequently asked questions

What is CVE-2017-17023?: 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.
How severe is CVE-2017-17023?: CVE-2017-17023 has a CVSS 3.x base score of 8.1, rated high severity. It is exploitable over network with high attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.
Is CVE-2017-17023 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (45th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2017-17023?: CVE-2017-17023 primarily affects Ncp-e Ncp Secure Entry Client. In total, 2 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2017-17023?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
When was CVE-2017-17023 published?: CVE-2017-17023 was published on 2019-04-09 and last updated on 2026-06-17.

References

Affected products (2)

cpe:2.3:a:ncp-e:ncp_secure_entry_client:10.11:32792:*:*:*:windows:*:*
cpe:2.3:a:sophos:ipsec_client:11.04:*:*:*:*:*:*:*

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