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Fencer Vulns
high 7.8

CVE-2025-34079 json

NSClient++ Authenticated Remote Code Execution via ExternalScripts API

published 2025-07-02 16 mo ago modified 2026-06-17 4 mo ago also EUVD-2025-19752

cvss
7.8
version 3.1, NVD
cisa kev
Not listed
not in CISA's catalog
epss
1.7%
EPSS 1.7% chance of exploitation in 30 days, percentile 77%
public exploits
1
Metasploit

Summary

An authenticated remote code execution vulnerability exists in NSClient++ version 0.5.2.35 when the web interface and ExternalScripts module are enabled. A remote attacker with the administrator password can authenticate to the web interface (default port 8443), inject arbitrary commands as external scripts via the /settings/query.json API, save the configuration, and trigger the script via the /query/{name} endpoint. The injected commands are executed with SYSTEM privileges, enabling full remote compromise.

This capability is an intended feature, but the lack of safeguards or privilege separation makes it risky when exposed to untrusted actors.

Timeline

  1. First public exploit (Metasploit exploit/windows/http/nscp_authenticated_rce)
  2. Published

CISA SSVC

Exploitation
Proof of concept is public
Automatable
no
Technical impact
total
Assessed
16 mo ago

Exploit prediction

1.70% chance of exploitation in the next 30 days, higher than 77% of all scored CVEs (FIRST EPSS, 2026-11-08).

Exploits and checks

  • Metasploit exploit/windows/http/nscp_authenticated_rce NSClient++ 0.5.2.35 - ExternalScripts Authenticated Remote Code Execution metasploit exploit, excellent rank, 2020-10-20
  • raw.githubusercontent.com https://raw.githubusercontent.com/rapid7/metasploit-framework/master/modules/exploits/windows/http/nscp_authenticated_rce.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
  • 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 7.5 CVSS:4.0/AV:N/AC:L/AT:P/PR:H/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N
CNA 4.0 7.5 CVSS:4.0/AV:N/AC:L/AT:P/PR:H/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-94 Improper Control of Generation of Code
  • CWE-306 Missing Authentication for Critical Functionality

References

Sources

Fencer Vulns 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.