Mozilla · Firefox Esr · CVE-2023-4581
**Name of the Vulnerable Software and Affected Versions**
Firefox versions prior to 117
Firefox ESR versions prior to 115.2
Thunderbird versions prior to 115.2
**Description**
The issue is related to insufficient warning about potentially hazardous actions, allowing a remote attacker to download arbitrary files. Specifically, Excel `.xll` add-in files did not have a blocklist entry in Firefox's executable blocklist, which enabled them to be downloaded without warnings about their potential harm.
**Recommendations**
For Firefox versions prior to 117, update to version 117 or later to resolve the issue.
For Firefox ESR versions prior to 115.2, update to version 115.2 or later to resolve the issue.
For Thunderbird versions prior to 115.2, update to version 115.2 or later to resolve the issue.