Mozilla · Firefox Esr · CVE-2021-23987
**Name of the Vulnerable Software and Affected Versions**
Firefox versions prior to 87
Firefox ESR versions prior to 78.9
Thunderbird versions prior to 78.9
**Description**
The issue is related to memory safety bugs and buffer copying without checking the size of input data, which could potentially allow an attacker to execute arbitrary code using a specially crafted website. Some of these bugs showed evidence of memory corruption.
**Recommendations**
For Firefox versions prior to 87, update to version 87 or later.
For Firefox ESR versions prior to 78.9, update to version 78.9 or later.
For Thunderbird versions prior to 78.9, update to version 78.9 or later.