CVE-2026-75877: TRENDnet TV-IP751WIC Buffer Overflow Bug

CVE-2026-75877 Overview

CVE-2026-75877 is a stack-based buffer overflow [CWE-119] in TRENDnet TV-IP751WIC firmware version 11.03.03. The flaw resides in the alphapd web server component and affects multiple functions including SystemNetworkChanged, SystemDDNSChanged, SystemEmailChanged, SystemFTPChanged, websCheckRealm, FUN_00432574, and FUN_0043372C. Attackers can trigger the overflow remotely over the network with low-privilege authentication. A public proof-of-concept has been released, increasing the likelihood of active exploitation attempts against exposed devices.

Critical Impact
Remote attackers with low privileges can corrupt the alphapd process stack to achieve code execution, hijack the device, and pivot into internal networks.

Affected Products

TRENDnet TV-IP751WIC IP camera
Firmware version 11.03.03
alphapd embedded web server component

Discovery Timeline

2026-08-18 - CVE-2026-75877 published to NVD
2026-08-20 - Last updated in NVD database

Technical Details for CVE-2026-75877

Vulnerability Analysis

The vulnerability exists in the alphapd HTTP daemon running on the TRENDnet TV-IP751WIC. Several request handlers copy attacker-controlled input into fixed-size stack buffers without validating length. The affected routines process configuration changes for networking, DDNS, email notifications, and FTP uploads, along with HTTP realm parsing in websCheckRealm. Overflowing these buffers overwrites saved return addresses and adjacent stack data. On typical MIPS or ARM embedded targets without stack canaries or full ASLR, the corruption enables reliable control-flow hijacking.

Root Cause

The root cause is the absence of bounds checking on user-supplied strings passed to stack-allocated buffers inside alphapd. Standard unsafe operations such as strcpy or sprintf variants copy request parameters directly into buffers of predetermined length. The affected functions include configuration handlers and the authentication realm parser, meaning the bug is reachable through multiple HTTP endpoints.

Attack Vector

An attacker sends a crafted HTTP request to the camera's management interface with an oversized parameter targeting one of the vulnerable handlers. Because websCheckRealm participates in HTTP authentication processing, a portion of the attack surface is reachable with minimal authentication context. Successful exploitation grants execution within the alphapd process, typically running as root on the device. A public proof-of-concept demonstrates the password-overflow vector; see the GitHub PoC Repository for technical details.

Detection Methods for CVE-2026-75877

Indicators of Compromise

Unexpected reboots or crashes of the alphapd process on TRENDnet TV-IP751WIC cameras
HTTP requests to management endpoints containing abnormally long parameter values, particularly in DDNS, email, FTP, or authentication fields
Outbound connections initiated by the camera to unfamiliar external hosts
New or modified configuration entries not matching administrative changes

Detection Strategies

Inspect HTTP traffic to camera management interfaces for parameter lengths exceeding expected sizes
Correlate camera device logs with network flow data to identify anomalous post-request behavior
Deploy IDS signatures matching the public PoC payload structure documented in the GitHub Source Code Directory

Monitoring Recommendations

Segment IP cameras onto isolated VLANs and monitor east-west traffic for lateral movement
Alert on any inbound access to camera HTTP interfaces from non-management subnets
Track firmware versions across the fleet to identify unpatched TV-IP751WIC units running 11.03.03

How to Mitigate CVE-2026-75877

Immediate Actions Required

Remove TV-IP751WIC cameras from direct internet exposure and block inbound access to the alphapd web interface
Restrict management access to a dedicated administrative network using firewall ACLs
Rotate any credentials that were configured on affected devices in case of prior compromise
Audit device configurations for unexpected DDNS, email, or FTP settings that could indicate tampering

Patch Information

At the time of publication, no vendor advisory or firmware update has been identified in the referenced sources. Consult VulDB CVE Details and TRENDnet support channels for updated patch availability. Until a fix is available, treat the device as end-of-support from a security standpoint if the model is no longer maintained.

Workarounds

Disable remote administration and require VPN access for any camera management
Place affected cameras behind a reverse proxy that enforces strict request-size limits on HTTP parameters
Replace TV-IP751WIC units with actively maintained models if a vendor patch is not forthcoming

bash

# Example firewall rule to block inbound access to camera web interface
iptables -A FORWARD -p tcp -d <camera_ip> --dport 80 -j DROP
iptables -A FORWARD -p tcp -d <camera_ip> --dport 443 -j DROP
# Allow only management subnet
iptables -I FORWARD -p tcp -s 10.10.20.0/24 -d <camera_ip> --dport 80 -j ACCEPT