tcpflow has TIM Element OOB Write in wifipcap

tcpflow is a TCP/IP packet demultiplexer. In versions up to and including 1.61, wifipcap parses 802.11 management frame elements and performs a length check on the wrong field when handling the TIM element. A crafted frame with a large TIM length can cause a 1-byte out-of-bounds write past `tim.bitmap[251]`. The overflow is small and DoS is the likely impact; code execution is potential, but still up in the air. The affected structure is stack-allocated in `handle_beacon()` and related handlers. As of time of publication, no known patches are available.