SOC status:Duty analyst on shift

UK Cyber Defence
VulnerabilityAnalyzed

CVE-2025-34079

An authenticated remote code execution vulnerability exists in NSClient++ version 0.5.2.35 when the web interface and ExternalScripts module are enabled.

HIGH 7.5EPSS 1.46%

Does this matter?

High impact if exploited, but EPSS currently rates exploitation as unlikely (1.46%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.

Description

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.

CVSS 4.0
7.5 HIGHCVSS: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/M
EPSS
1.46% probability · 72th percentile
CISA KEV
Not listed
Weakness
CWE-94, CWE-306
Affected
nsclient/nsclient\+\+
Source
disclosure@vulncheck.com

Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.