CVE-2024-2815 Overview
CVE-2024-2815 is a stack-based buffer overflow vulnerability affecting the Tenda AC15 wireless router running firmware version 15.03.05.20_multi. The flaw resides in the R7WebsSecurityHandler function within the /goform/execCommand endpoint, specifically in how the Cookie Handler component processes the password argument. An unauthenticated attacker can trigger the overflow remotely over the network, leading to memory corruption and potential arbitrary code execution. The vendor was contacted prior to public disclosure but did not respond, and the exploit details have been published, increasing risk to exposed devices.
Critical Impact
Unauthenticated remote attackers can corrupt stack memory on affected Tenda AC15 routers, enabling potential code execution and full device compromise.
Affected Products
- Tenda AC15 router (hardware)
- Tenda AC15 firmware version 15.03.05.20_multi
- Earlier firmware builds sharing the vulnerable R7WebsSecurityHandler implementation (e.g., V15.03.05.18 per public documentation)
Discovery Timeline
- 2024-03-22 - CVE-2024-2815 published to NVD
- 2024-11-21 - Last updated in NVD database
Technical Details for CVE-2024-2815
Vulnerability Analysis
The vulnerability is a stack-based buffer overflow [CWE-121] in the R7WebsSecurityHandler function of the Tenda AC15 web management interface. This function processes HTTP Cookie headers sent to the /goform/execCommand endpoint. The handler extracts the password value from the cookie and copies it into a fixed-size stack buffer without validating the input length. Supplying an oversized password value overruns the stack frame, overwriting the saved return address and adjacent local variables. Because the AC15 web server runs with elevated privileges and lacks modern stack protections common on embedded MIPS targets, an attacker with network reachability to the management interface can corrupt control flow.
Root Cause
The root cause is missing bounds checking on attacker-controlled cookie data. The R7WebsSecurityHandler routine treats the password cookie field as trusted input and uses an unsafe string copy into a stack buffer. No length validation, canary, or size-limited copy primitive is enforced before the write occurs.
Attack Vector
Exploitation requires only network access to the router's HTTP management interface. The attacker sends a crafted HTTP request to /goform/execCommand containing a Cookie header with an oversized password field. No authentication or user interaction is required. Devices exposing the management interface to the WAN are reachable from the internet, while LAN-only exposure still permits exploitation by any host on the local network or via cross-site request forwarding techniques.
No verified public exploit code is reproduced here. Technical write-up details are available in the GitHub Vulnerability Documentation and VulDB #257670.
Detection Methods for CVE-2024-2815
Indicators of Compromise
- HTTP POST or GET requests to /goform/execCommand containing abnormally long password values inside the Cookie header
- Unexpected reboots, watchdog resets, or httpd process crashes on Tenda AC15 devices
- Outbound connections from the router to unfamiliar hosts following inbound web requests
- New or modified DNS, DHCP, or routing configuration on the device without administrative action
Detection Strategies
- Inspect web server and httpd logs for requests targeting /goform/execCommand with Cookie payloads exceeding typical session token lengths
- Deploy network IDS signatures that match overlong password= cookie fields directed at Tenda management interfaces
- Monitor for repeated connection attempts to TCP port 80 or 443 on router management addresses from untrusted sources
Monitoring Recommendations
- Capture and review router system logs centrally for crash traces and abnormal restarts
- Alert on any external (WAN-side) access to the AC15 administrative interface
- Track firmware version inventory across deployed Tenda devices to identify unpatched units
How to Mitigate CVE-2024-2815
Immediate Actions Required
- Disable remote (WAN-side) administration on all Tenda AC15 routers until a fixed firmware is available
- Restrict access to the LAN-side management interface using ACLs or VLAN segmentation
- Replace internet-exposed AC15 units in production environments with supported, actively patched hardware
- Rotate any administrative credentials that may have transited the affected interface
Patch Information
As of the last NVD update on 2024-11-21, the vendor has not published a security advisory or patched firmware for CVE-2024-2815. Per the disclosure record, Tenda did not respond to the researcher's outreach. Administrators should monitor the Tenda support portal for firmware updates and apply them immediately upon release.
Workarounds
- Block inbound TCP/80 and TCP/443 to the router from untrusted networks at an upstream firewall
- Place the router behind a network segment that filters HTTP requests to /goform/execCommand
- Disable the web management interface entirely if device management can be performed out-of-band
- Consider replacing affected devices with vendor-supported alternatives if no patch is forthcoming
# Example upstream firewall rule to block external access to the router web UI
iptables -I FORWARD -p tcp -d <ROUTER_IP> --dport 80 -j DROP
iptables -I FORWARD -p tcp -d <ROUTER_IP> --dport 443 -j DROP
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
