NULL pointer dereference in libpcap before 1.10.5 with remote packet capture support

Vulnerability Description

Remote packet capture support is disabled by default in libpcap. When a user builds libpcap with remote packet capture support enabled, one of the functions that become available is pcap_findalldevs_ex(). One of the function arguments can be a filesystem path, which normally means a directory with input data files. When the specified path cannot be used as a directory, the function receives NULL from opendir(), but does not check the return value and passes the NULL value to readdir(), which causes a NULL pointer derefence.

References

• https://github.com/the-tcpdump-group/libpcap/commit/0f8a103469ce87d2b8d68c5130a46ddb7fb5eb29
• https://github.com/the-tcpdump-group/libpcap/commit/8a633ee5b9ecd9d38a587ac9b204e2380713b0d6