GSS-NTLMSSP vulnerable to out-of-bounds read when decoding target information

GSS-NTLMSSP, a mechglue plugin for the GSSAPI library that implements NTLM authentication, has an out-of-bounds read when decoding target information prior to version 1.2.0. The length of the `av_pair` is not checked properly for two of the elements which can trigger an out-of-bound read. The out-of-bounds read can be triggered via the main `gss_accept_sec_context` entry point and could cause a denial-of-service if the memory is unmapped. The issue is fixed in version 1.2.0.