In Wireshark 2.2.0 to 2.2.5 and 2.0.0 to 2.0.11, the IMAP dissector could crash, triggered by packet injection or a malformed capture file. This was addressed in epan/dissectors/packet-imap.c by calculating a line's end correctly.
Exploitability
AV:NAC:LPR:NUI:NScope
S:UImpact
C:NI:NA:H7.5/CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H