XLL file extensions were downloadable without warnings
3Vexday Risk Score
No sign of exploitation. No public exploitation artifact known so far.
ssvc Trackepss 0.6%
exploitation probability
0.6%top 54% of all CVEs
observed exploitation
nono source reports it
Excel `.xll` add-in files did not have a blocklist entry in Firefox's executable blocklist which allowed them to be downloaded without any warning of their potential harm. This vulnerability affects Firefox < 117, Firefox ESR < 102.15, Firefox ESR < 115.2, Thunderbird < 102.15, and Thunderbird < 115.2.
References
https://bugzilla.mozilla.org/show_bug.cgi?id=1843758https://www.mozilla.org/security/advisories/mfsa2023-34/https://www.mozilla.org/security/advisories/mfsa2023-35/https://www.mozilla.org/security/advisories/mfsa2023-36/https://www.mozilla.org/security/advisories/mfsa2023-37/https://www.mozilla.org/security/advisories/mfsa2023-38/