CVE-2021-38509

Description

Due to an unusual sequence of attacker-controlled events, a Javascript alert() dialog with arbitrary (although unstyled) contents could be displayed over top an uncontrolled webpage of the attacker's choosing. This vulnerability affects Firefox < 94, Thunderbird < 91.3, and Firefox ESR < 91.3.

Category

4.3
CVSS
Severity: Medium
CVSS 3.1 •
CVSS 2.0 •
EPSS 0.48%
Vendor Advisory debian.org Vendor Advisory debian.org Vendor Advisory gentoo.org Vendor Advisory gentoo.org Vendor Advisory mozilla.org Vendor Advisory mozilla.org Vendor Advisory mozilla.org Vendor Advisory mozilla.org
Affected: Mozilla Firefox
Affected: Mozilla Thunderbird
Affected: Mozilla Firefox ESR
Published at:
Updated at:

References

Link Tags
https://www.mozilla.org/security/advisories/mfsa2021-49/ vendor advisory
https://www.mozilla.org/security/advisories/mfsa2021-50/ vendor advisory
https://www.mozilla.org/security/advisories/mfsa2021-48/ vendor advisory
https://bugzilla.mozilla.org/show_bug.cgi?id=1718571 vendor advisory issue tracking permissions required
https://www.debian.org/security/2021/dsa-5026 third party advisory vendor advisory
https://lists.debian.org/debian-lts-announce/2021/12/msg00030.html third party advisory mailing list
https://www.debian.org/security/2022/dsa-5034 vendor advisory mailing list third party advisory
https://lists.debian.org/debian-lts-announce/2022/01/msg00001.html third party advisory mailing list
https://security.gentoo.org/glsa/202202-03 third party advisory vendor advisory
https://security.gentoo.org/glsa/202208-14 third party advisory vendor advisory

Frequently Asked Questions

What is the severity of CVE-2021-38509?
CVE-2021-38509 has been scored as a medium severity vulnerability.
How to fix CVE-2021-38509?
To fix CVE-2021-38509, make sure you are using an up-to-date version of the affected component(s) by checking the vendor release notes. As for now, there are no other specific guidelines available.
Is CVE-2021-38509 being actively exploited in the wild?
As for now, there are no information to confirm that CVE-2021-38509 is being actively exploited. According to its EPSS score, there is a ~0% probability that this vulnerability will be exploited by malicious actors in the next 30 days.
What software or system is affected by CVE-2021-38509?
CVE-2021-38509 affects Mozilla Firefox, Mozilla Thunderbird, Mozilla Firefox ESR.
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