Overview
A critical stack-based buffer overflow vulnerability has been disclosed in the TRENDnet TEW-821DAP wireless access point, affecting firmware version 2.2.01b05. Tracked as CVE-2026-77946, the flaw carries a maximum CVSS score of 10.0 and is remotely exploitable, potentially enabling full arbitrary code execution on affected devices.
As of August 23, 2026, no patch is available from TRENDnet.
Technical Details
The vulnerability resides in /cgi-bin/apply_time.cgi, specifically within the uci_safe_get function responsible for processing the device's NTP Timezone Configuration component. An attacker can trigger the stack overflow by supplying malformed input to one or more of the following parameters:
system.ntp.serversystem.ntp.enable_servercameo.time.time_zonecameo.cameo.syslog_server
Successful exploitation allows an attacker to overwrite the call stack, redirect execution flow, and achieve remote code execution (RCE) on the device — potentially gaining root-level control of the access point.
Risk Assessment
| Factor | Detail |
|---|---|
| CVSS Score | 10.0 (Critical) |
| Attack Vector | Network (remote) |
| Authentication | Not specified |
| Patch Available | No |
| Public Exploit | Yes — disclosed via exploit feeds |
The disclosure of a public exploit with no vendor patch significantly raises the risk for any deployment where the device management interface is internet-accessible.
Affected Products
- Vendor: TRENDnet
- Device: TEW-821DAP Wireless Access Point
- Firmware: 2.2.01b05
Other firmware versions have not been publicly confirmed as affected or unaffected.
Mitigation
Until TRENDnet releases a patched firmware update, administrators should take the following steps:
- Isolate the management interface — Restrict access to the device's admin panel to trusted LAN segments only. Do not expose it to the internet.
- Disable remote management — If the device supports remote management over WAN, disable it immediately.
- Restrict NTP configuration access — If possible, limit which hosts can reach the NTP configuration endpoint.
- Monitor for firmware updates — Watch TRENDnet's official support pages for a patched firmware release.
- Consider replacement — For production environments requiring high security, evaluate replacing the device with a supported alternative until a fix is issued.