Cyber Resilience

CVE-2025-34079

RCE in Nsclient\+\+ 0.5.2.35

Published
02 July 2025
Modified
17 June 2026
CVSS Score v4 7.5
Click a component to see what it means
Raw vectorCVSS: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
EPSS Score 0.013 67th percentile
Risk Priority 70 floored blend · peak EPSS

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, exploitation aligns with the MITRE ATT&CK technique Exploit Public-Facing Application (T1190); ranked in the top 33% of CVEs by exploit likelihood; it is not currently listed in the CISA KEV catalog; a public proof-of-concept is referenced.

The strongest mitigations our analysis identified map to AC-14 (Permitted Actions Without Identification or Authentication) and IA-2 (Identification and Authentication (Organizational Users)) — see the control section below for these in your framework.

Deeper analysis AI-assisted summary

Synthesised by an AI model from the NVD description and linked references — a reading aid, not an authoritative source.

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.

OWASP Top 10 for Web (2025)

EU & UK References

Vulnerability Data

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…

more

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

MITRE ATT&CK Enterprise Techniques

T1190 Exploit Public-Facing Application Initial Access
Adversaries may attempt to exploit a weakness in an Internet-facing host or system to initially access a network.
T1059 Command and Scripting Interpreter Execution
Adversaries may abuse command and script interpreters to execute commands, scripts, or binaries.
T1059.001 PowerShell Execution
Adversaries may abuse PowerShell commands and scripts for execution.
T1059.002 AppleScript Execution
Adversaries may abuse AppleScript for execution.
T1059.004 Unix Shell Execution
Adversaries may abuse Unix shell commands and scripts for execution.
T1059.005 Visual Basic Execution
Adversaries may abuse Visual Basic (VB) for execution.
Derived from this CVE’s CWE(s) via the direct CWE→ATT&CK cross-walk.

CVEs Like This One

CVE-2026-71319Shared CWE-306, CWE-94
CVE-2019-9082Shared CWE-306, CWE-94
CVE-2025-34089Shared CWE-306, CWE-94
CVE-2026-41179Shared CWE-306, CWE-94
CVE-2021-39144Shared CWE-306, CWE-94
CVE-2025-3248Shared CWE-306, CWE-94
CVE-2025-34077Shared CWE-306, CWE-94
CVE-2026-1340Shared CWE-94
CVE-2024-54724Shared CWE-94
CVE-2013-3906Shared CWE-94

Affected Assets

nsclient
nsclient\+\+
0.5.2.35

Mitigating Controls

Control response

Prevent
Stop it (NIST 800-53)

Detect
Catch it (NIST detect / respond)

Harden
Shrink the surface (DISA STIG)
  • 6 hardening rules · 3 OS baselines
Validate
Prove the fix (OWASP ASVS)
  • V6.2.3
  • V6.4.4
  • V10.4.16
  • V12.1.3

Mitigating Controls (NIST 800-53 r5) AI

Directly mandates unique identification and authentication of users before access to functions requiring identity.

Extends the same authentication requirement to non-organizational users accessing critical functionality.

Requires authentication of services before they can invoke or expose critical functions.

Explicitly identifies and limits actions permitted without authentication, preventing critical functions from being exposed.

Developer testing and evaluation finds code paths that accept and execute externally influenced strings.

Input validation directly stops untrusted data from being used to construct executable code without neutralization.

Mitigating Controls (NIST CSF 2.0) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→CSF cross-walk (authority under review) — links open the control.

PR.AA-03 full match
prevents

Directly requires authentication of users/services/hardware, which eliminates missing authentication for critical functions.

PR.PS-06 mostly match
prevents

PR.PS-06's SDLC practices directly target injection flaws via secure coding and testing (mostly), yet as a single broad outcome it leaves many code-generation specifics unaddressed (partial).

PR.AA-01 partial match
prevents

Managing identities and credentials is a prerequisite for authentication but does not itself enforce it on critical functions.

PR.AA-05 partial match
prevents

Defining and enforcing authorizations assumes prior authentication and therefore only partially mitigates the absence of authentication.

PR.IR-01 partial match
prevents

Protecting networks from unauthorized access can be undermined by missing authentication but does not address the root authentication gap.

PR.DS-10 none match
prevents

PR.DS-10 protects runtime data confidentiality/integrity but has no bearing on neutralizing externally influenced input during code generation, so neither direction shows any preventive effect.

Mitigating Controls (ISO/IEC 27001:2022 Annex A) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→ISO cross-walk (authority under review) — links open the control.

prevents

The control explicitly calls for authentication before any critical function is reached, eliminating the possibility of bypassing authentication for high-value operations.

prevents

Mandating authentication requirements for critical functions at the requirements-gathering stage ensures that essential operations are not left unprotected by missing login or verification mechanisms.

mitigates

Mandating authentication for network services and critical functions stops attackers from invoking sensitive operations without credentials, closing gaps where authentication is absent for important capabilities.

prevents

Security engineering principles insist on authentication and authorization for every critical function, eliminating entry points that lack any access control mechanism.

prevents

Banning unapproved code samples and unauthenticated web services, combined with secure-coding standards and SAST, prevents the dynamic generation or inclusion of attacker-supplied code.

none

Requiring strong authentication and access-privilege enablement for remote connections ensures that critical functions cannot be invoked without proper verification, closing a gap that would otherwise allow unauthenticated use.

Hardening callouts derived

Configuration rules from DISA STIG baselines that bear on weaknesses of the type cited by this CVE. Each rule is shown with the relationship its mapping actually records, against the CWE it was authored against. Derived via CVE→CWE over `controls_xwalks` (authoritative rows only; rows rated `none` are excluded).

Oracle Linux 8 (2 rules)
  • V-248585 OL 8 must require reauthentication when using the "sudo" command. prevents CWE-306
  • V-248827 OL 8 must not have the rsh-server package installed. prevents CWE-306
RHEL 7 (2 rules)
  • V-204442 The Red Hat Enterprise Linux operating system must not have the rsh-server package installed. prevents CWE-306
  • V-237635 The Red Hat Enterprise Linux operating system must require re-authentication when using the "sudo" command. prevents CWE-306
RHEL 8 (2 rules)
  • V-230492 RHEL 8 must not have the rsh-server package installed. prevents CWE-306
  • V-237643 RHEL 8 must require re-authentication when using the "sudo" command. prevents CWE-306

References