TRENDnet — CraftedSignal Threat Feedhttps://feed.craftedsignal.io/vendors/trendnet/Trending threats, MITRE ATT&CK coverage, and detection metadata — refreshed continuously.Hugoenhello@craftedsignal.iohello@craftedsignal.ioSat, 02 May 2026 08:16:28 +0000TRENDnet TEW-821DAP Firmware Update Buffer Overflow Vulnerabilityhttps://feed.craftedsignal.io/briefs/2024-01-trendnet-buffer-overflow/Sat, 02 May 2026 08:16:28 +0000hello@craftedsignal.iohttps://feed.craftedsignal.io/briefs/2024-01-trendnet-buffer-overflow/A buffer overflow vulnerability exists in TRENDnet TEW-821DAP version 1.12B01, allowing a remote attacker to execute arbitrary code by manipulating the 'str' argument in the auto_update_firmware function of the Firmware Update component.CVE-2026-7607 describes a buffer overflow vulnerability affecting TRENDnet TEW-821DAP version 1.12B01. The vulnerability resides within the auto_update_firmware function of the Firmware Update component. A remote attacker can exploit this flaw by sending a crafted request with a maliciously oversized ‘str’ argument, leading to a buffer overflow. Although the CVSS score is high, the vendor has stated that the affected product reached its end-of-life 8 years ago and is no longer supported, significantly reducing the risk of widespread exploitation. This lack of support means no patches or updates will be provided, leaving vulnerable devices exposed if still in operation.

Attack Chain

  1. Attacker identifies a vulnerable TRENDnet TEW-821DAP device running firmware version 1.12B01.
  2. Attacker sends a specially crafted network packet to the device, targeting the Firmware Update component.
  3. The packet includes a malicious ‘str’ argument exceeding the buffer’s allocated size in the auto_update_firmware function.
  4. The device attempts to process the firmware update, copying the oversized ‘str’ argument into the undersized buffer.
  5. The buffer overflow overwrites adjacent memory regions, potentially including critical program data or execution pointers.
  6. Attacker hijacks control of the execution flow by overwriting the return address with the address of malicious code.
  7. The device executes the attacker’s arbitrary code with the privileges of the Firmware Update component.
  8. The attacker gains control of the device, potentially enabling further malicious activities.

Impact

Successful exploitation of this buffer overflow vulnerability could allow an attacker to gain complete control over the affected TRENDnet TEW-821DAP device. This could lead to unauthorized network access, data theft, or the device being used as a bot in a larger attack. Given that the affected product is EOL, the number of actively exploitable devices is likely low, but any remaining devices are at significant risk since no patch will be available.

Recommendation

  • Identify and isolate any TRENDnet TEW-821DAP devices running firmware version 1.12B01 on your network. Consider decommissioning them if possible due to the end-of-life status and lack of security updates.
  • Monitor network traffic for suspicious packets targeting the Firmware Update component of TRENDnet devices. Implement intrusion detection rules to identify and block potentially malicious requests (see example Sigma rule below).
  • Since this is a buffer overflow on a network device, monitor for unusual process creation or network connections originating from TRENDnet devices.
  • Deploy the provided Sigma rule to detect attempts to exploit the vulnerability by monitoring for unusual data lengths in network traffic related to firmware updates.
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