CVE-2019-11703: Heap buffer overflow in icalparser.c
	  A flaw in Thunderbird's implementation of iCal causes a heap
	    buffer overflow in parser_get_next_char when processing certain
	    email messages, resulting in a potentially exploitable crash.
	  CVE-2019-11704: Heap buffer overflow in icalvalue.c
	  A flaw in Thunderbird's implementation of iCal causes a heap
	    buffer overflow in icalmemory_strdup_and_dequote when processing
	    certain email messages, resulting in a potentially exploitable
	    crash.
	  CVE-2019-11705: Stack buffer overflow in icalrecur.c
	  A flaw in Thunderbird's implementation of iCal causes a stack
	    buffer overflow in icalrecur_add_bydayrules when processing
	    certain email messages, resulting in a potentially exploitable
	    crash.
	  CVE-2019-11706: Type confusion in icalproperty.c
	  A flaw in Thunderbird's implementation of iCal causes a type
	    confusion in icaltimezone_get_vtimezone_properties when
	    processing certain email messages, resulting in a crash.