CVE-2025-6150: Totolink X15 Buffer Overflow Vulnerability

CVE-2025-6150 Overview

CVE-2025-6150 is a buffer overflow vulnerability in the TOTOLINK X15 router running firmware version 1.0.0-B20230714.1105. The flaw resides in the /boafrm/formMultiAP endpoint of the HTTP POST request handler. Attackers can manipulate the submit-url argument to trigger the overflow condition. The issue is classified under [CWE-119] (Improper Restriction of Operations within the Bounds of a Memory Buffer). Exploitation occurs remotely over the network and requires only low-level privileges. Public disclosure of the exploit technique has occurred through third-party vulnerability databases, increasing the risk of opportunistic attacks against exposed devices.

Critical Impact
Remote attackers can corrupt memory in the router's web server process by sending a crafted HTTP POST request to /boafrm/formMultiAP, potentially leading to arbitrary code execution or device compromise.

Affected Products

TOTOLINK X15 router (hardware)
TOTOLINK X15 firmware version 1.0.0-B20230714.1105
CPE: cpe:2.3:o:totolink:x15_firmware:1.0.0-b20230714.1105

Discovery Timeline

2025-06-17 - CVE-2025-6150 published to NVD
2026-06-17 - Last updated in NVD database

Technical Details for CVE-2025-6150

Vulnerability Analysis

The vulnerability exists in the TOTOLINK X15 embedded web server, which is based on the Boa HTTP daemon. The /boafrm/formMultiAP handler processes HTTP POST requests used to configure multi-AP wireless settings. When the handler parses the submit-url parameter, it copies attacker-controlled data into a fixed-size stack or heap buffer without validating the input length.

This unchecked copy operation results in adjacent memory being overwritten. On MIPS-based SOHO routers like the X15, such overflows commonly overwrite saved return addresses on the stack. Attackers can redirect execution flow to attacker-controlled data or ROP gadgets already present in the firmware binary.

The attack surface is exposed through the router's administrative web interface. The exploit has been documented publicly in third-party sources, including GitHub CVE Documentation and VulDB #312625.

Root Cause

The root cause is the absence of bounds checking in the routine that processes the submit-url POST parameter within formMultiAP. Standard unsafe string handling primitives such as strcpy or sprintf are typical culprits in this class of Boa-based router firmware. The application trusts the length of client-supplied input rather than enforcing a maximum size before copying.

Attack Vector

An attacker sends a crafted HTTP POST request to /boafrm/formMultiAP with an oversized submit-url value. The request must originate from a network path reachable by the device's HTTP service. Successful exploitation corrupts process memory in the web server, enabling denial of service or code execution in the context of the router's management daemon, which typically runs with elevated privileges.

No verified proof-of-concept code is included here. Refer to the GitHub PoC Document for the disclosed technical details.

Detection Methods for CVE-2025-6150

Indicators of Compromise

HTTP POST requests to /boafrm/formMultiAP containing an unusually long submit-url parameter value
Repeated crashes, reboots, or web interface unavailability on TOTOLINK X15 devices
Unexpected outbound connections originating from the router to unfamiliar destinations following administrative requests

Detection Strategies

Inspect HTTP request logs on network middleboxes for POST requests to /boafrm/formMultiAP with parameter lengths exceeding typical configuration values
Deploy network intrusion detection signatures that flag oversized submit-url fields directed at TOTOLINK management interfaces
Correlate router availability metrics with inbound HTTP administrative traffic to identify crash-inducing probes

Monitoring Recommendations

Monitor administrative interfaces of SOHO routers for anomalous POST traffic from non-management network segments
Enable syslog forwarding from the router to a centralized log platform to capture crash and restart events
Alert on any exposure of the router's HTTP interface to the public internet

How to Mitigate CVE-2025-6150

Immediate Actions Required

Restrict access to the TOTOLINK X15 web administration interface to trusted management VLANs only
Disable remote WAN-side administration if enabled
Rotate administrative credentials and enforce strong passwords to reduce the risk of authenticated exploitation
Inventory all TOTOLINK X15 devices running firmware 1.0.0-B20230714.1105 across the environment

Patch Information

As of the latest NVD update, no vendor patch has been referenced in the advisory. Consult Totolink Security Resources for firmware updates addressing this issue. Until a fix is published, treat affected devices as exposed and apply compensating network controls.

Workarounds

Place affected routers behind an upstream firewall that blocks unsolicited HTTP traffic to the management interface
Segment IoT and network infrastructure devices away from user workstations and servers
Consider replacing end-of-support TOTOLINK X15 units with actively maintained equipment if no patch becomes available

bash

# Example iptables rule to restrict access to the router web interface
# Allow management access only from the trusted subnet 192.168.10.0/24
iptables -A INPUT -p tcp --dport 80 -s 192.168.10.0/24 -j ACCEPT
iptables -A INPUT -p tcp --dport 80 -j DROP