CVE-2026-38060 Overview
CVE-2026-38060 is a command injection vulnerability affecting the Tenda 5G03 router running firmware version V05.03.02.04 (Version 1.0). The flaw resides in the action_unlock_sim function, where the pin parameter is passed to a shell context without proper sanitization. An unauthenticated attacker on the network can inject arbitrary operating system commands by crafting a malicious request to the affected endpoint. Successful exploitation yields command execution in the router's underlying operating system, compromising confidentiality, integrity, and availability of the device. The weakness is classified as [CWE-78] Improper Neutralization of Special Elements used in an OS Command.
Critical Impact
Unauthenticated network attackers can execute arbitrary OS commands on the router, leading to full device compromise and potential pivoting into the connected network.
Affected Products
- Tenda 5G03 router
- Firmware version V05.03.02.04
- Version 1.0 (vulnerable action_unlock_sim handler)
Discovery Timeline
- 2026-06-15 - CVE-2026-38060 published to NVD
- 2026-06-17 - Last updated in NVD database
Technical Details for CVE-2026-38060
Vulnerability Analysis
The Tenda 5G03 web management interface exposes a SIM unlock action handled by the action_unlock_sim function. The function reads the user-supplied pin parameter from the HTTP request and incorporates it into an OS command without validation or escaping. Attackers can append shell metacharacters such as ;, |, or backticks to the pin value to break out of the intended command context. The injected payload runs with the privileges of the web server process, typically root on consumer router firmware. The vulnerability requires no authentication, no user interaction, and is reachable over the network.
Root Cause
The root cause is unsanitized concatenation of the pin HTTP parameter into a shell command string within action_unlock_sim. The firmware does not validate that pin conforms to a numeric format or apply allow-list filtering before invoking a system call. This pattern matches [CWE-78] OS Command Injection. See the GitHub PoC Repository for technical details on the vulnerable code path.
Attack Vector
An attacker sends a crafted HTTP request to the router's management interface targeting the action_unlock_sim endpoint. The malicious pin parameter contains shell metacharacters followed by attacker-chosen commands. The router's web service passes the string to a shell, executing the injected commands. Exposure increases when the management interface is reachable from the WAN or from untrusted segments of the LAN.
No verified exploitation code is published. Refer to the GitHub PoC Repository for the proof-of-concept disclosure.
Detection Methods for CVE-2026-38060
Indicators of Compromise
- HTTP requests to the router management interface containing shell metacharacters (;, |, &&, backticks, $()) inside the pin parameter.
- Unexpected outbound connections from the router to attacker-controlled infrastructure following requests to action_unlock_sim.
- New or modified processes, cron entries, or /tmp artifacts on the device shortly after web requests to the SIM unlock endpoint.
Detection Strategies
- Inspect HTTP traffic destined for the Tenda 5G03 administrative interface and alert on non-numeric characters in the pin field.
- Deploy network IDS signatures that match action_unlock_sim request bodies containing shell metacharacters.
- Correlate router web access logs with subsequent anomalous DNS or outbound traffic from the device.
Monitoring Recommendations
- Forward router syslog and web access logs to a centralized logging platform for analysis.
- Monitor management plane traffic for unauthenticated POST requests to action_unlock_sim.
- Track firmware versions across the fleet to identify devices running V05.03.02.04.
How to Mitigate CVE-2026-38060
Immediate Actions Required
- Restrict access to the router's web management interface to trusted internal hosts only and disable WAN-side administration.
- Place affected Tenda 5G03 devices behind a network segment that blocks untrusted HTTP traffic to the management port.
- Inventory and identify all Tenda 5G03 units running firmware V05.03.02.04 for remediation tracking.
Patch Information
No vendor patch is referenced in the NVD entry at the time of publication. Monitor Tenda's official support channels for a firmware update that addresses the action_unlock_sim command injection. Apply the fixed firmware as soon as it becomes available.
Workarounds
- Disable remote management on the WAN interface to reduce the attack surface.
- Enforce strict ACLs on the LAN to limit which hosts can reach the router's HTTP administrative interface.
- Place the device behind a network firewall that filters HTTP requests containing shell metacharacters in form parameters.
- Replace the affected device with a supported model if no firmware update is published.
# Configuration example: block external access to the router admin interface
# Adjust the upstream firewall to drop inbound HTTP/HTTPS to the router's management IP
iptables -A FORWARD -d <router_mgmt_ip> -p tcp --dport 80 -j DROP
iptables -A FORWARD -d <router_mgmt_ip> -p tcp --dport 443 -j DROP
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
