Vulnerability in Nsclient Nsclient\+\+

CVE-2025-34078

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.

EPSS: 0.005 (40.7th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 7.8 (High). Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H.

Affected products

Weakness classification (CWE)

Public proof-of-concept exploits

References

Frequently asked questions

What is CVE-2025-34078?
CVE-2025-34078 is a high-severity vulnerability in Nsclient Nsclient\+\+, classified under Insufficiently Protected Credentials. CVSS score: 7.8/10. Published 2025-07-02.
How severe is CVE-2025-34078?
High severity. CVSS v3 base score is 7.8 out of 10.
Is CVE-2025-34078 known to be exploited?
1 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.