A Format String vulnerablity exists in TRENDnet TEW-755AP 1.11B03, TEW-755AP2KAC 1.11B03, TEW-821DAP2KAC 1.11B03, and TEW-825DAP 1.11B03, which could let a remote malicious user cause a denial of service due to a logic bug at address 0x40dcd0 when calling fprintf with "%s: key len = %d, too long\n" format. The two variables seem to be put in the wrong order. The vulnerability could be triggered by sending the POST request to apply_cgi with a long and unknown key in the request body.

References

• https://nvd.nist.gov/vuln/detail/CVE-2021-28846
• https://github.com/zyw-200/EQUAFL/blob/main/TRENDnet%20ticket.pdf