The rpcap client code that processes a RPCAP_MSG_PACKET message received from the server incorrectly validates its headers. A malicious server can send a crafted message and cause the client to treat up to 20 bytes of the client process memory beyond the end of the buffer as if it was a part of the captured packet.
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.