The vulnerability of Firefox browsers, Firefox ESR, and the Thunderbird email client arises from the mixing of symbols from the “Canadian Syllabics” block with symbols from other blocks, allowing attackers to perform spear-phishing attacks.

The vulnerability of Firefox browsers, Firefox ESR, and the email client Thunderbird is related to the mixing of symbols from the “Canadian Syllabics” block with symbols from other blocks. Exploiting this vulnerability allows a remote attacker to perform spam attacks...