Code: handle_mlppp(netdissect_options *ndo,
             const u_char *p, int length)
{
     if (!ndo->ndo_eflag)
         ND_PRINT((ndo, "MLPPP, "));
 
     ND_PRINT((ndo, "seq 0x%03x, Flags [%s], length %u",
            (EXTRACT_16BITS(p))&0x0fff, /* only support 12-Bit sequence space for now */
            bittok2str(ppp_ml_flag_values, "none", *p & 0xc0),
           length));
}

Vulnerability Type: 
CWE ID: CWE-125
Summary: The PPP parser in tcpdump before 4.9.2 has a buffer over-read in print-ppp.c:handle_mlppp().
Commit Message: CVE-2017-13038/PPP: Do bounds checking.

This fixes a buffer over-read discovered by Brian 'geeknik' Carpenter.

Add a test using the capture file supplied by Katie Holly.