CVE-2026-38708: Router Command Injection RCE Vulnerability

CVE-2026-38708 Overview

CVE-2026-38708 is a command injection vulnerability [CWE-77] affecting multiple Cudy router firmware versions. The flaw resides in the system.setclock interface, which fails to sanitize user-supplied input before passing it to a system shell. Unauthenticated attackers can send crafted input to execute arbitrary commands as root over the network.

Affected firmware includes TR1200 v2.4.15, TR3000 v2.4.21, WR300 v2.4.25, WR1200 v2.4.23, WR1300 v2.4.22, WR1500 v2.3.10, WR3000 v2.4.19, WR3600 v2.3.16, and WR6500 v2.3.15.

Critical Impact
Unauthenticated network attackers can achieve root-level remote code execution on affected Cudy routers via the system.setclock interface.

Affected Products

Cudy TR1200 v2.4.15 and TR3000 v2.4.21
Cudy WR300 v2.4.25, WR1200 v2.4.23, WR1300 v2.4.22, and WR1500 v2.3.10
Cudy WR3000 v2.4.19, WR3600 v2.3.16, and WR6500 v2.3.15

Discovery Timeline

2026-07-31 - CVE-2026-38708 published to NVD
2026-08-03 - Last updated in NVD database

Technical Details for CVE-2026-38708

Vulnerability Analysis

The vulnerability lives in the system.setclock interface exposed by the router's management service. This interface accepts clock configuration parameters and passes them to an underlying operating system command without proper neutralization of shell metacharacters. Attackers can append arbitrary commands using shell separators such as ;, &&, or backticks, and the router executes those commands with root privileges.

Because the router web management daemon runs as root, successful exploitation yields full device control. Attackers can pivot into internal networks, intercept traffic, modify firmware, or add the device to a botnet. The EPSS score of 2.619% (83.9th percentile) indicates above-average exploitation probability relative to other CVEs.

Root Cause

The root cause is improper neutralization of special elements used in an OS command [CWE-77]. The system.setclock handler concatenates user input directly into a shell command string rather than using safe execution primitives with argument arrays or applying strict allow-list validation of the clock parameters.

Attack Vector

Exploitation requires network reachability to the router's management interface. No authentication or user interaction is needed. An attacker sends a crafted request to system.setclock containing shell metacharacters and an appended command payload. The router executes the injected command as root and returns control to the attacker through reverse shells, command output exfiltration, or persistence mechanisms.

See the Cudy Security Advisory Cudy-SA-26-7 for vendor technical details.

// No verified proof-of-concept code is available.
// Refer to the Cudy security advisory for technical specifics.

Detection Methods for CVE-2026-38708

Indicators of Compromise

Unexpected outbound connections originating from router management IP addresses, particularly to unfamiliar remote hosts on non-standard ports.
Unusual processes or shell activity spawned by the router's web management daemon outside routine configuration windows.
Modifications to router configuration, DNS settings, or firmware images that were not initiated by administrators.

Detection Strategies

Inspect HTTP or HTTPS requests to router management endpoints for system.setclock parameters containing shell metacharacters such as ;, |, &, $(, or backticks.
Monitor router syslog output for unexpected command execution events and failed authentication attempts against management interfaces.
Correlate network flow telemetry with router management traffic to identify anomalous command-and-control patterns following configuration requests.

Monitoring Recommendations

Forward router logs and network flow data into a centralized SIEM for retention and correlation across the environment.
Baseline expected management traffic to affected Cudy routers and alert on deviations in request volume, source IP, or payload structure.
Track firmware versions across the router fleet and alert when devices remain on vulnerable versions after patches are released.

How to Mitigate CVE-2026-38708

Immediate Actions Required

Restrict access to router management interfaces to trusted internal networks and block WAN-side administrative access.
Inventory all Cudy routers in the environment and cross-reference firmware versions against the affected list.
Rotate administrative credentials on affected devices and audit configurations for unauthorized modifications.

Patch Information

Cudy has published guidance in the Cudy Security Advisory Cudy-SA-26-7. Apply the firmware updates released by Cudy for each affected model as soon as they become available for your device.

Workarounds

Disable remote management on the WAN interface and restrict LAN-side management access to a dedicated administrative VLAN.
Place affected routers behind an upstream firewall that filters access to management ports until firmware updates are applied.
Segment router management networks from user and IoT networks to limit lateral movement following any successful exploitation.

bash

# Example: restrict router management access to a trusted admin subnet
# (adapt syntax to your upstream firewall or router ACL platform)
iptables -A INPUT -p tcp --dport 443 -s 10.10.0.0/24 -j ACCEPT
iptables -A INPUT -p tcp --dport 443 -j DROP
iptables -A INPUT -p tcp --dport 80  -s 10.10.0.0/24 -j ACCEPT
iptables -A INPUT -p tcp --dport 80  -j DROP