CVE-2018-14779

A buffer overflow issue was discovered in the Yubico-Piv 1.5.0 smartcard
driver. The file lib/ykpiv.c contains the following code in the function
ykpiv_transfer_data(): {% highlight c %} if(*out_len + recv_len - 2 >
max_out) { fprintf(stderr, “Output buffer to small, wanted to write %lu,
max was %lu.”, *out_len + recv_len - 2, max_out); } if(out_data) {
memcpy(out_data, data, recv_len - 2); out_data += recv_len - 2; *out_len +=
recv_len - 2; } {% endhighlight %} – it is clearly checked whether the
buffer is big enough to hold the data copied using memcpy(), but no error
handling happens to avoid the memcpy() in such cases. This code path can
be triggered with malicious data coming from a smartcard.

Bugs

• <http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=906128&gt;