Mozilla · Firefox Esr · CVE-2021-43545
**Name of the Vulnerable Software and Affected Versions**
Mozilla Thunderbird versions prior to 91.4.0
Mozilla Firefox ESR versions prior to 91.4.0
Mozilla Firefox versions prior to 95
**Description**
The issue is related to the execution of a loop with an unreachable exit condition, potentially allowing a remote attacker to cause a denial of service via an infinite loop error when using the `Location API`. This could lead to severe application hangs and crashes.
**Recommendations**
For Mozilla Thunderbird versions prior to 91.4.0, update to version 91.4.0 or later.
For Mozilla Firefox ESR versions prior to 91.4.0, update to version 91.4.0 or later.
For Mozilla Firefox versions prior to 95, update to version 95 or later.
As a temporary workaround, consider restricting the use of the `Location API` in loops to minimize the risk of exploitation.