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.