CVE-2025-3542: H3C Magic Router RCE Vulnerability

CVE-2025-3542 Overview

CVE-2025-3542 is a command injection vulnerability affecting H3C Magic NX15, Magic NX400, and Magic R3010 routers up to firmware version V100R014. The flaw resides in the FCGI_WizardProtoProcess function handling requests to /api/wizard/getsyncpppoecfg within the HTTP POST request handler. An authenticated attacker on the adjacent network can inject arbitrary operating system commands through crafted parameters. A public proof-of-concept has been disclosed, increasing the risk of opportunistic exploitation against exposed devices.

Critical Impact
Successful exploitation allows an adjacent attacker with low privileges to execute arbitrary commands on the router, compromising confidentiality, integrity, and availability of the device and the network it serves.

Affected Products

H3C Magic NX15 (up to V100R014)
H3C Magic NX400 (up to V100R014)
H3C Magic R3010 (up to V100R014)

Discovery Timeline

2025-04-14 - CVE-2025-3542 published to NVD
2026-06-17 - Last updated in NVD database

Technical Details for CVE-2025-3542

Vulnerability Analysis

The vulnerability is a command injection flaw categorized under [CWE-74] (Improper Neutralization of Special Elements in Output Used by a Downstream Component). It affects the FCGI_WizardProtoProcess function invoked when the router processes HTTP POST requests directed at the /api/wizard/getsyncpppoecfg endpoint. This endpoint appears to handle PPPoE synchronization configuration as part of the router setup wizard.

The endpoint accepts user-supplied input that is passed to a downstream shell interpreter without adequate sanitization or neutralization of shell metacharacters. As a result, an attacker can append additional commands that execute in the context of the router's web management process, typically running with elevated privileges on embedded Linux firmware. The attack requires adjacent network access, meaning the attacker must be positioned on the local network segment, such as through a wireless connection or a compromised internal host.

Root Cause

The root cause is missing input validation in the FCGI_WizardProtoProcess handler. Parameters submitted to /api/wizard/getsyncpppoecfg are concatenated into shell command strings without escaping or safe API usage. Shell metacharacters such as backticks, semicolons, and command substitution operators are passed through to the underlying system()-style execution primitive.

Attack Vector

An attacker with valid low-level credentials sends a crafted HTTP POST request to /api/wizard/getsyncpppoecfg from within the local network. Injected payloads in fields consumed by the PPPoE wizard configuration parser are interpreted as shell commands by the FastCGI backend. The vulnerability manifests entirely within the router's built-in web management interface. Refer to the GitHub Gist PoC and VulDB entry #304581 for technical exploitation details.

Detection Methods for CVE-2025-3542

Indicators of Compromise

HTTP POST requests to /api/wizard/getsyncpppoecfg containing shell metacharacters such as ;, |, &, backticks, or $(...) in PPPoE parameter fields.
Unexpected outbound connections originating from the router management plane to unfamiliar external hosts.
Router configuration changes, new administrative accounts, or modified firewall rules that were not initiated by administrators.
Anomalous CPU or memory utilization on the router coinciding with wizard endpoint activity.

Detection Strategies

Inspect network flows and web application firewall logs for POST traffic targeting /api/wizard/ endpoints from non-administrative hosts.
Deploy signatures on network sensors that flag shell metacharacters in HTTP POST bodies destined for H3C management interfaces.
Correlate authentication events on the router with subsequent wizard API activity to identify low-privilege accounts exercising configuration paths.

Monitoring Recommendations

Enable and centralize syslog forwarding from affected H3C devices to a SIEM for retention and correlation.
Alert on any access to the router web UI from segments that should not manage network infrastructure, such as guest wireless subnets.
Track firmware version and configuration hashes to detect unauthorized modifications on Magic NX15, NX400, and R3010 devices.

How to Mitigate CVE-2025-3542

Immediate Actions Required

Upgrade affected H3C Magic NX15, NX400, and R3010 devices to a firmware version later than V100R014 once the vendor publishes a fixed release.
Restrict access to the router administrative interface to a dedicated management VLAN and trusted administrator hosts only.
Rotate all router administrative credentials and remove unused low-privilege accounts that could be leveraged for the attack.
Audit routers for signs of prior exploitation, including modified configurations and unexpected services or accounts.

Patch Information

H3C recommends upgrading the affected firmware. Fixed releases and advisories are distributed through the H3C Software Download portal and the H3C support knowledge base. Administrators should verify firmware integrity and cross-reference the release notes for command injection remediation before deployment.

Workarounds

Segment the router management network so that only administrator workstations can reach the web management port.
Disable remote management on wireless and guest interfaces to reduce the adjacent attack surface.
Implement upstream access control lists that block HTTP POST requests to /api/wizard/getsyncpppoecfg from untrusted internal hosts until a patched firmware is applied.

bash

# Example ACL restricting access to router management to a trusted host
# (apply on an upstream L3 switch or firewall)
access-list 110 permit tcp host 10.10.0.25 host 10.10.0.1 eq 80
access-list 110 permit tcp host 10.10.0.25 host 10.10.0.1 eq 443
access-list 110 deny   tcp any host 10.10.0.1 eq 80
access-list 110 deny   tcp any host 10.10.0.1 eq 443
access-list 110 permit ip any any