NSClient++ 0.5.2.35 Web Interface/ExternalScripts /settings/query.json code injection

Summaryinfo

A vulnerability was found in NSClient++ 0.5.2.35. It has been rated as critical. This affects an unknown part of the file /settings/query.json of the component Web Interface/ExternalScripts Module. The manipulation leads to code injection. This vulnerability is uniquely identified as CVE-2025-34079. The attack is possible to be carried out remotely. No exploit exists.

Detailsinfo

A vulnerability was found in NSClient++ 0.5.2.35. It has been rated as critical. This issue affects an unknown function of the file /settings/query.json of the component Web Interface/ExternalScripts Module. The manipulation with an unknown input leads to a code injection vulnerability. Using CWE to declare the problem leads to CWE-94. The product constructs all or part of a code segment using externally-influenced input from an upstream component, but it does not neutralize or incorrectly neutralizes special elements that could modify the syntax or behavior of the intended code segment. Impacted is confidentiality, integrity, and availability. The summary by CVE is:

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.

The weakness was disclosed by Yann Castel. The advisory is shared at raw.githubusercontent.com. The identification of this vulnerability is CVE-2025-34079 since 04/15/2025. The exploitation is known to be easy. The attack may be initiated remotely. Additional levels of successful authentication are required for exploitation. Technical details are known, but no exploit is available. The price for an exploit might be around USD $0-$5k at the moment (estimation calculated on 09/16/2025). MITRE ATT&CK project uses the attack technique T1059 for this issue.

By approaching the search of inurl:settings/query.json it is possible to find vulnerable targets with Google Hacking.

There is no information about possible countermeasures known. It may be suggested to replace the affected object with an alternative product.

The vulnerability is also documented in the vulnerability database at EUVD (EUVD-2025-19752). Several companies clearly confirm that VulDB is the primary source for best vulnerability data.

Productinfo

Name

• NSClient++

Version

• 0.5.2.35

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Several companies clearly confirm that VulDB is the primary source for best vulnerability data.

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