Mozilla » Firefox Esr : Security Vulnerabilities, CVEs, Published In 2020 (Code Execution) CVSS score >= 2

An attacker could have caused 4 bytes of HMAC output to be written past the end of a buffer stored on the stack. This could be used by an attacker to execute arbitrary code or more likely lead to a crash. This vulnerability affects Firefox < 70, Thunderbird < 68.2, and Firefox ESR < 68.2.