ASA-2019-00353 – Mozilla Thunderbird: Stack-based buffer overflow in icalrecur_add_bydayrules()

A stack-based buffer overflow has been identified in the Thunderbird email client. The issue is present in the libical implementation, which was forked from upstream libical version 0.47. The issue can be triggered remotely, when an attacker sends a specially crafted calendar attachment and does not require user interaction. It might be used by a remote attacker to crash or gain remote code execution in the client system.