CVE-2025-57572 Overview
CVE-2025-57572 is a buffer overflow vulnerability affecting the Tenda F3 router running firmware version V12.01.01.48_multi and later. The flaw resides in the goform/setParentControl endpoint, where the onlineList parameter is processed without proper bounds checking. Attackers can send crafted HTTP requests over the network to trigger memory corruption on the device. The weakness is classified under [CWE-120] (Buffer Copy without Checking Size of Input). Successful exploitation can compromise the confidentiality, integrity, and availability of the affected router, though the attack complexity is high.
Critical Impact
Network-based buffer overflow in the parental control handler of Tenda F3 routers can lead to memory corruption, service disruption, and potential code execution on the embedded device.
Affected Products
- Tenda F3 router (hardware)
- Tenda F3 firmware version V12.01.01.48_multi
- Tenda F3 firmware versions released after V12.01.01.48_multi
Discovery Timeline
- 2025-09-10 - CVE-2025-57572 published to NVD
- 2026-07-05 - Last updated in NVD database
Technical Details for CVE-2025-57572
Vulnerability Analysis
The vulnerability affects the parental control handler exposed at the goform/setParentControl endpoint of the Tenda F3 router web management interface. When a request is submitted, the firmware copies data from the onlineList HTTP parameter into a fixed-size stack or heap buffer without validating the input length. Oversized input overwrites adjacent memory, corrupting control structures used by the embedded HTTP server. This class of flaw is common in Tenda's goform handlers, which historically use unchecked string copy operations such as strcpy or sprintf. Because the vulnerable endpoint is reachable through the router's management interface, exploitation does not require prior authentication in typical deployments.
Root Cause
The root cause is missing bounds validation on user-controlled input processed by the setParentControl function. The firmware trusts the length of the onlineList parameter supplied in the POST body and writes it into a fixed-size destination buffer. This meets the [CWE-120] pattern of classic buffer overflow through unchecked buffer copy.
Attack Vector
An attacker sends a crafted HTTP POST request to /goform/setParentControl with an overlong onlineList value. On a network with routable access to the device management interface, the request reaches the embedded web server and triggers the overflow. The vulnerability is exploitable over the network without user interaction, but the attack complexity is high because reliable exploitation depends on device-specific memory layout and MIPS architecture constraints.
A public proof-of-concept describing the request format is available at the GitHub PoC for CVE-2025-57572. No verified exploitation code is reproduced here.
Detection Methods for CVE-2025-57572
Indicators of Compromise
- HTTP POST requests to /goform/setParentControl containing abnormally long onlineList parameter values.
- Repeated reboots, crashes, or unresponsiveness of the Tenda F3 web management interface following inbound requests.
- Unexpected changes to parental control configuration entries on the device.
Detection Strategies
- Inspect HTTP traffic destined for router management interfaces and flag POST bodies where onlineList exceeds a reasonable length threshold.
- Deploy IDS/IPS signatures that match oversized parameter values in requests to Tenda goform endpoints.
- Correlate router availability telemetry with inbound HTTP requests to identify crash patterns consistent with buffer overflow attempts.
Monitoring Recommendations
- Log all administrative HTTP requests to the router and forward them to a centralized SIEM for baseline analysis.
- Monitor for unauthorized access attempts to the router management network segment.
- Track firmware versions across deployed Tenda F3 devices to identify vulnerable hosts.
How to Mitigate CVE-2025-57572
Immediate Actions Required
- Restrict access to the router web management interface to trusted management VLANs or hosts only.
- Disable remote (WAN-side) management on all Tenda F3 devices.
- Change default administrative credentials and enforce strong passwords on the management interface.
- Isolate affected devices from untrusted network segments until a vendor patch is available.
Patch Information
No vendor advisory or firmware patch has been published for CVE-2025-57572 at the time of writing. Monitor the Tenda support site for firmware updates addressing the setParentControl handler. Apply updates immediately once released.
Workarounds
- Block inbound HTTP requests to /goform/setParentControl at an upstream firewall where feasible.
- Segment router management traffic onto a dedicated network unreachable from user or guest networks.
- Replace end-of-life Tenda F3 devices with actively supported hardware if the vendor does not issue a fix.
# Example: restrict router management access to a single admin host
iptables -A INPUT -p tcp --dport 80 -s 192.0.2.10 -j ACCEPT
iptables -A INPUT -p tcp --dport 80 -j DROP
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
