CVE-2025-9528 Overview
CVE-2025-9528 is an OS command injection vulnerability in the Linksys E1700 wireless router running firmware version 1.0.0.4.003. The flaw resides in the systemCommand function within /goform/systemCommand, where the command argument is passed to the underlying operating system without proper sanitization [CWE-77]. Attackers can manipulate this parameter to execute arbitrary shell commands on the device. The exploit has been publicly disclosed and may be utilized by threat actors. According to the published advisory, the vendor was contacted but did not respond to the disclosure.
Critical Impact
Authenticated remote attackers can inject operating system commands through the /goform/systemCommand endpoint, leading to arbitrary command execution on affected Linksys E1700 routers.
Affected Products
- Linksys E1700 router (hardware)
- Linksys E1700 firmware version 1.0.0.4.003
- Deployments exposing the web management interface to untrusted networks
Discovery Timeline
- 2025-08-27 - CVE-2025-9528 published to NVD
- 2026-06-17 - Last updated in NVD database
Technical Details for CVE-2025-9528
Vulnerability Analysis
The vulnerability is classified as OS command injection under [CWE-77]. The systemCommand handler exposed at /goform/systemCommand accepts a command parameter from HTTP requests. The handler passes this parameter into a shell execution context without input validation or escaping. Attackers append shell metacharacters such as ;, |, or backticks to inject additional commands that run with the privileges of the web server process, which on consumer routers typically runs as root.
The attack is launched over the network and requires high privileges, meaning the attacker must hold valid administrative credentials or reach an authenticated session. Once exploited, the attacker gains command execution on the embedded Linux operating system. This enables firmware tampering, persistence implants, traffic interception, or pivoting into adjacent network segments.
Root Cause
The root cause is the absence of input sanitization in the systemCommand function. User-supplied content from the command argument flows directly into a system call without validation against an allowlist or escaping of shell metacharacters. This pattern violates secure coding practices for executing operating system commands.
Attack Vector
An authenticated attacker sends a crafted HTTP request to /goform/systemCommand with a malicious value in the command parameter. The injected payload appends shell control characters and additional commands. Public proof-of-concept details are available in the GitHub PoC Repository and on VulDB #321545. The EPSS score indicates a relatively elevated probability of exploitation activity compared to most CVEs.
Detection Methods for CVE-2025-9528
Indicators of Compromise
- HTTP requests to /goform/systemCommand containing shell metacharacters such as ;, &&, |, or backticks in the command parameter.
- Unexpected outbound connections from the router to attacker-controlled infrastructure.
- Unauthorized modifications to router configuration, DNS settings, or firmware images.
Detection Strategies
- Inspect web server and management interface logs on the router for POST or GET requests targeting /goform/systemCommand with suspicious parameter values.
- Deploy network monitoring to flag administrative requests originating from non-administrative IP ranges.
- Correlate authentication events with subsequent command-injection patterns observed in HTTP traffic.
Monitoring Recommendations
- Forward router syslog and web access logs to a centralized SIEM for retention and analytics.
- Alert on any HTTP traffic to /goform/ endpoints from outside the management VLAN.
- Track baseline outbound traffic from infrastructure devices and alert on deviations.
How to Mitigate CVE-2025-9528
Immediate Actions Required
- Restrict access to the router web management interface to trusted internal addresses only.
- Disable remote (WAN-side) administration on all Linksys E1700 devices.
- Rotate administrative credentials and enforce strong, unique passwords on the device.
- Plan replacement of end-of-support consumer routers where vendor patches are not forthcoming.
Patch Information
No vendor patch has been published at the time of disclosure. The advisory notes that Linksys was contacted but did not respond. Operators should consult the Linksys Official Website for updated firmware notifications and consider migrating to actively supported hardware until a fix is released.
Workarounds
- Place the router behind an upstream firewall and block external access to TCP ports used by the management interface.
- Segment the router management interface onto a dedicated VLAN reachable only by administrative hosts.
- Where feasible, replace the Linksys E1700 with a currently supported model receiving security updates.
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
