CVE-2024-7180 Overview
CVE-2024-7180 is a buffer overflow vulnerability in the TOTOLINK A3600R router running firmware version 4.1.2cu.5182_B20201102. The flaw resides in the setPortForwardRules function within /cgi-bin/cstecgi.cgi. Attackers can trigger the overflow by manipulating the comment argument in a crafted request. The issue is classified under CWE-120 (Classic Buffer Overflow) and can be exploited remotely over the network. Public disclosure has occurred through VulDB entry #272601 and a technical write-up on GitHub. TOTOLINK was contacted before disclosure but did not respond, leaving affected devices without a vendor patch.
Critical Impact
Remote authenticated attackers can trigger a buffer overflow in the router's CGI handler, potentially leading to arbitrary code execution or device compromise.
Affected Products
- TOTOLINK A3600R router hardware
- TOTOLINK A3600R firmware version 4.1.2cu.5182_B20201102
- Deployments exposing the /cgi-bin/cstecgi.cgi interface to untrusted networks
Discovery Timeline
- 2024-07-29 - CVE-2024-7180 published to the National Vulnerability Database
- 2026-06-17 - Last updated in NVD database
Technical Details for CVE-2024-7180
Vulnerability Analysis
The vulnerability lives in the setPortForwardRules handler exposed by the router's cstecgi.cgi binary. This CGI endpoint processes port-forwarding configuration requests submitted through the administrative interface. The handler accepts a comment parameter intended to store a user-supplied label for each port-forwarding rule. The vulnerable function copies this parameter into a fixed-size stack buffer without validating the input length. Supplying an oversized comment value overflows the destination buffer and corrupts adjacent stack memory, including saved return addresses. Successful exploitation can crash the CGI process, disrupt network services, or lead to arbitrary code execution in the context of the CGI handler. The impact extends to confidentiality, integrity, and availability of the router, which typically runs its web services as a privileged user.
Root Cause
The root cause is the absence of bounds checking on the comment argument before it is written into a stack buffer. The developer relied on unsafe string handling routines without enforcing a maximum length on attacker-controlled input, matching the CWE-120 pattern.
Attack Vector
An attacker with network reachability to the router's web management interface sends a crafted HTTP request to /cgi-bin/cstecgi.cgi invoking setPortForwardRules with an oversized comment field. The CVSS 4.0 vector indicates that low privileges are required, meaning access to an authenticated management session or default credentials is a prerequisite. Because the exploit has been publicly disclosed in the GitHub IoT Vulnerability Document, the barrier to weaponization is low. Devices exposing the management interface to the internet are especially at risk.
No verified proof-of-concept code is reproduced here. Technical details are available in the VulDB entry #272601 and the associated GitHub write-up.
Detection Methods for CVE-2024-7180
Indicators of Compromise
- HTTP POST requests to /cgi-bin/cstecgi.cgi containing unusually long comment parameter values within setPortForwardRules calls
- Unexpected reboots, watchdog resets, or crashes of the router's web management daemon following administrative requests
- New or modified port-forwarding rules that were not created by an authorized administrator
Detection Strategies
- Inspect web server and CGI logs for setPortForwardRules invocations with comment values exceeding typical label lengths, such as more than 128 bytes.
- Deploy network intrusion detection signatures that flag requests to cstecgi.cgi containing oversized or non-printable payloads in the comment field.
- Correlate management-interface authentication events with subsequent CGI crashes to identify probing attempts.
Monitoring Recommendations
- Forward router syslog output to a centralized logging platform and alert on repeated CGI process failures.
- Monitor for administrative HTTP sessions originating from untrusted or geographically unexpected source addresses.
- Baseline outbound traffic from the router itself to detect post-exploitation command-and-control activity.
How to Mitigate CVE-2024-7180
Immediate Actions Required
- Restrict access to the router's web management interface to trusted administrative networks only, and disable WAN-side management.
- Change any default or shared administrator credentials to strong, unique passwords to reduce the chance of an attacker satisfying the authentication prerequisite.
- Audit existing port-forwarding rules and remove any entries that cannot be attributed to authorized changes.
Patch Information
No vendor patch is available. TOTOLINK did not respond to the disclosure attempt documented in the VulDB submission. Organizations still operating the TOTOLINK A3600R on firmware 4.1.2cu.5182_B20201102 should monitor the vendor's website for future firmware releases and consider replacing the device with a supported model.
Workarounds
- Segment vulnerable routers onto isolated management VLANs and block inbound access to TCP ports serving the web interface from untrusted networks.
- Place the device behind an upstream firewall that filters requests to /cgi-bin/cstecgi.cgi from unauthorized source addresses.
- Where feasible, decommission the A3600R and migrate to a router model that receives active security updates.
# Example: block external access to the router management interface on an upstream firewall (iptables)
iptables -A FORWARD -p tcp -d <router_ip> --dport 80 -m iprange ! --src-range 10.0.0.0-10.0.0.255 -j DROP
iptables -A FORWARD -p tcp -d <router_ip> --dport 443 -m iprange ! --src-range 10.0.0.0-10.0.0.255 -j DROP
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
