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Fencer Intel
high 7.8

CVE-2025-34078 json

NSClient++ 0.5.2.35 Local Privilege Escalation via ExternalScripts and Web Interface

published last yr. modified 4mo ago also EUVD-2025-19753

cvss
7.8
version 3.1, NVD
cisa kev
Not listed
not in CISA's catalog
epss
0.7%
EPSS 0.7% chance of exploitation in 30 days, percentile 53%
public exploits
1
Metasploit

Summary

A local privilege escalation vulnerability exists in NSClient++ 0.5.2.35 when both the web interface and ExternalScripts features are enabled. The configuration file (nsclient.ini) stores the administrative password in plaintext and is readable by local users. By extracting this password, an attacker can authenticate to the NSClient++ web interface (typically accessible on port 8443) and abuse the ExternalScripts plugin to inject and execute arbitrary commands as SYSTEM by registering a custom script, saving the configuration, and triggering it via the API.

This behavior is documented but insecure, as the plaintext credential exposure undermines access isolation between local users and administrative functions.

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Timeline

  1. First public exploit (Metasploit exploit/windows/local/nscp_pe)
  2. Published

CISA SSVC

Exploitation
Proof of concept is public
Automatable
no
Technical impact
partial
Assessed
last yr.

Exploit prediction

0.71% chance of exploitation in the next 30 days, higher than 53% of all scored CVEs (FIRST EPSS, 2026-11-09).

Exploits and checks

  • Metasploit exploit/windows/local/nscp_pe NSClient++ 0.5.2.35 - Privilege escalation metasploit exploit, excellent rank, 2020-10-20
  • raw.githubusercontent.com https://raw.githubusercontent.com/rapid7/metasploit-framework/master/modules/exploits/windows/local/nscp_pe.rb referenced PoC, tagged "exploit" by a source, unverified
  • exploit-db.com https://www.exploit-db.com/exploits/48360 referenced PoC, tagged "exploit" by a source, unverified
  • exploit-db.com https://www.exploit-db.com/exploits/46802 referenced PoC, tagged "exploit" by a source, unverified
  • vulncheck.com https://vulncheck.com/advisories/nsclient-localtoremote-system-compromise referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by version score vector
CNA 4.0 7.3 CVSS:4.0/AV:L/AC:L/AT:P/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N
CNA 4.0 7.3 CVSS:4.0/AV:L/AC:L/AT:P/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/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
NVD 3.1 7.8 CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Affected products

  • NSClient++ NSClient++

Classification

Weakness
  • CWE-522 Insufficiently Protected Credentials

References

Sources

Fencer Intel keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.