CVE-2025-34079
Published: 02 July 2025
Summary
CVE-2025-34079 is a high-severity Code Injection (CWE-94) vulnerability in Nsclient Nsclient\+\+. Its CVSS base score is 7.5 (High).
Operationally, ranked in the top 1.2% of CVEs by exploit likelihood; it is not currently listed in the CISA KEV catalog; a public proof-of-concept is referenced.
Deeper analysis
NSClient++ version 0.5.2.35 contains an authenticated remote code execution vulnerability when both the web interface and ExternalScripts module are enabled. The flaw allows an attacker who possesses the administrator password to authenticate over the default HTTPS port 8443 and use the /settings/query.json endpoint to register arbitrary external scripts, after which the configuration is saved and the script is invoked through the /query/{name} endpoint. Execution occurs with SYSTEM privileges, resulting in full host compromise. The affected functionality is documented as an intended feature, yet the implementation provides no additional safeguards or privilege separation.
An attacker with valid administrative credentials can remotely inject and execute operating-system commands without further user interaction. The attack requires network access to the web interface and knowledge of the administrator password; once the script is registered and triggered, the resulting process runs in the SYSTEM context, enabling arbitrary code execution, persistence, and lateral movement.
Public references include a Metasploit module, an Exploit-DB entry, and a VulnCheck advisory that document the attack path and provide proof-of-concept code. No official vendor patch or configuration-hardening guidance is referenced in the supplied materials.
The EPSS score stands at 0.7309 with an identical recorded peak, indicating sustained exploitation interest following disclosure.
EU & UK References
- 🇪🇺 ENISA EUVD: EUVD-2025-19752
Vulnerability details
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…
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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.
- CWE(s)
Related Threats
No named actor attribution yet. ATT&CK technique mapping in progress for this CVE.
Affected Assets
Mitigating Controls
Likely Mitigating Controls AI
Per-CVE control mapping for this CVE has not run yet; the list below is derived from the weakness types (CWEs) cited in the NVD entry.
Requires established identification and authentication to unlock, mitigating missing authentication for continued system access.
Requiring identification and rationale for actions allowed without authentication ensures critical functions are not left unprotected by forcing review of authentication requirements.
Authorizing mobile device connections to organizational systems ensures authentication is performed for this critical access function.
Guarantees critical functions are protected by mandatory invocation of the access control mechanism.
Auditing sessions makes it possible to detect access to critical functions without required authentication.
The assessment process confirms authentication is present and effective for critical functions, preventing exploitation from missing authentication.
Certification assesses that critical functions have required authentication controls in place.
Disabling non-essential functions and services eliminates the need to secure them, reducing exposure from missing authentication on unnecessary components.