rpcapd can allocate up to 65536 bytes per each RPCAP_MSG_UPDATEFILTER_REQ or RPCAP_MSG_STARTCAP_REQ message received from the client, but it never frees the memory, so it leaks memory even under normal use. A malicious client can cause the server to leak memory substantially faster.
The problem is specific to the remote packet capture code, which is not enabled in the default build configuration.
A functional exploit exists.
Upgrade to libpcap 1.10.7.