SOC status:Duty analyst on shift

UK Cyber Defence
VulnerabilityModified

CVE-2021-43538

By misusing a race in our notification code, an attacker could have forcefully hidden the notification for pages that had received full screen and pointer lock access, which could have been used for spoofing attacks.

MEDIUM 4.3EPSS 1.16%

Does this matter?

Lower severity and a low EPSS score (1.16%). Track it; it rarely justifies an emergency change on its own.

Description

By misusing a race in our notification code, an attacker could have forcefully hidden the notification for pages that had received full screen and pointer lock access, which could have been used for spoofing attacks. This vulnerability affects Thunderbird < 91.4.0, Firefox ESR < 91.4.0, and Firefox < 95.

CVSS 3.1
4.3 MEDIUMCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:L/A:N
EPSS
1.16% probability · 65th percentile
CISA KEV
Not listed
Weakness
CWE-362
Affected
mozilla/firefox · mozilla/firefox esr · mozilla/thunderbird · debian/debian linux
Source
security@mozilla.org

References

Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.