EW-7478APC (1.04) - CraftedSignal Threat Feedhttps://feed.craftedsignal.io/products/ew-7478apc-1.04/Trending threats, MITRE ATT&CK coverage, and detection metadata. Fed continuously.Hugoenhello@craftedsignal.iohello@craftedsignal.ioMon, 17 Aug 2026 00:42:27 +0000https://feed.craftedsignal.io/favicon-32x32.pngCraftedSignal Threat Feedhttps://feed.craftedsignal.io/3232https://feed.craftedsignal.io/favicon.svgStack-based Buffer Overflow in Edimax EW-7478APChttps://feed.craftedsignal.io/briefs/2026-08-edimax-buffer-overflow/Mon, 17 Aug 2026 00:42:27 +0000hello@craftedsignal.iohttps://feed.craftedsignal.io/briefs/2026-08-edimax-buffer-overflow/Edimax EW-7478APC version 1.04 is vulnerable to a stack-based buffer overflow in the formWanTcpipSetup function, allowing for remote code execution via the pppUserName parameter.A stack-based buffer overflow vulnerability has been identified in the Edimax EW-7478APC router, specifically within firmware version 1.04. The vulnerability resides in the formWanTcpipSetup function, accessible via the /goform/formWanTcpipSetup endpoint. An authenticated remote attacker can trigger this overflow by sending a specially crafted input to the pppUserName parameter. This flaw allows for the execution of arbitrary code on the affected device or can result in a denial-of-service condition. Publicly available exploit code exists, increasing the risk of exploitation. The vendor has not provided a patch or response to the disclosure. Defenders should note that this vulnerability requires authenticated access, but its remote nature and the availability of exploit material pose a significant risk to internal network segments where these devices are deployed.

Attack Chain

  1. Attacker performs network reconnaissance to identify reachable Edimax EW-7478APC management interfaces.
  2. Attacker obtains valid administrative or user credentials via secondary means (e.g., credential stuffing or default password exploitation).
  3. Attacker authenticates to the web-based management interface.
  4. Attacker crafts a malicious HTTP POST request targeting the /goform/formWanTcpipSetup endpoint.
  5. Attacker injects a long string payload into the pppUserName parameter of the POST body.
  6. The web server process fails to perform sufficient boundary checks on the pppUserName input before copying it into a stack-based buffer.
  7. The overflow overwrites the return address, enabling redirection of execution flow to arbitrary attacker-supplied shellcode.
  8. Final objective is achieved: arbitrary command execution or system crash.

Impact

Successful exploitation allows for complete compromise of the router, potentially providing an attacker with a pivot point into the local network. With a CVSS v3.1 score of 9.9, this vulnerability represents a critical risk to small office and home office (SOHO) deployments. If exploited, attackers could intercept traffic, perform man-in-the-middle attacks, or deploy further malicious payloads. Given the lack of a vendor patch, the only effective mitigation is to restrict management interface access to trusted networks or replace affected hardware.

Recommendation

  • Restrict access to the management web interface of all Edimax EW-7478APC devices to a dedicated management VLAN or trusted IP addresses via firewall rules.
  • Monitor internal network traffic for unauthorized HTTP POST requests directed at /goform/formWanTcpipSetup.
  • Audit logs for failed authentication attempts preceding any interaction with management endpoints.
  • Isolate affected devices from the internet until a firmware update is provided by the vendor.
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