CVE-2021-38509

high

Published 2021-11-03 · Modified 2021-11-04

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CVSS v3

—

CVSS v4 NEW

—

not yet in upstream

VIR risk

8.0

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.

Predictions

Exploit likelihood

20%

Patch ETA

—

Heuristic predictions, AS-IS, for prioritization only.

Mitigations

No mitigations published for this CVE yet.

The vendor-content worker queues fetches as references arrive (check back in a few minutes). Or — if you've already worked around this in production — publish your fix to the community-verified tier.

✚ Propose a mitigation on Community → Mitigations published via the community go through AI scoring + 2 human reviewers + 7-day silent objection window before landing here with source_tier=community-verified.

OS impact

Arch Fixed 1 release

Version	Status	Fixed in
—	Fixed	`91.3.0-1`

Debian Fixed 5 releases

Version	Status	Fixed in
trixie	Fixed	`91.3.0esr-1`
sid	Fixed	`94.0-1`
forky	Fixed	`91.3.0esr-1`
bullseye	Fixed	`91.4.1esr-1~deb11u1`
bookworm	Fixed	`91.3.0esr-1`

Red Hat Fixed 1 release

Version	Status	Fixed in
8	Fixed	—

Rocky Linux Fixed 1 release

Version	Status	Fixed in
8	Fixed	—

References

Community-verified mitigations for this CVE will appear above when contributors publish them.

Verify integrity in audit chain (admin only). AS-IS.