Home/CVE/Due to an unusual sequence of attacker-controlled events, a Javascript alert() dialog with arbitrary (although unstyled)
CVE

CVE-2021-38509

Due to an unusual sequence of attacker-controlled events, a Javascript alert() dialog with arbitrary (although unstyled)

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.

MEDIUM · CVSS 4.3 EPSS 0.00407
Monitor
  • No active-exploitation, high-EPSS, or public-exploit signals - routine patching cadence
Sigma rules1 YARA rules0
⬡

Weakness Classification

CWE-1021Improper Restriction of Rendered UI Layers or Frames
▤

Affected Products & Versions

4
mozilla firefox< 94.0
mozilla firefox esr< 91.3.0
mozilla thunderbird< 91.3.0
debian linuxall versions
◈

Sigma Hunt Rules

1
Exact rules name this CVE ID. Product rules name an affected product in their title. Related rules cover techniques used by actors who exploited this CVE. Showing the most relevant matches; the complete related set is on the full drill-down.
producthighSQLite Firefox Profile Data DB Access
▣

Scoring & Timeline

4.3
MEDIUM · CVSS v3.1 · security@mozilla.org
View on NVD
Attack Vector
Network Adjacent Local Physical
Attack Complexity
Low High
Privileges Required
None Low High
User Interaction
None Required
Scope
Unchanged Changed
Confidentiality
None Low High
Integrity
None Low High
Availability
None Low High
Published to NVD08 Dec 2021 · 10:15 PM
CVSS VectorCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:L/A:N
⚑

Vendor Advisories

22
suse-csafopenSUSE-SU-2024:14572-1
suse-csafopenSUSE-SU-2024:11607-1
suse-csafopenSUSE-SU-2024:11614-1
usnUSN-5248-1
suse-csafopenSUSE-SU-2021:1635-1
🔗

References & Sources

10
Source URLs (vendor pages, mailing lists, write-ups). Exploit/PoC links are in their own section above to avoid duplication.
https://bugzilla.mozilla.org/show_bug.cgi?id=1718571Issue TrackingPermissions RequiredVendor Advisory
https://lists.debian.org/debian-lts-announce/2021/12/msg00030.htmlMailing ListThird Party Advisory
https://lists.debian.org/debian-lts-announce/2022/01/msg00001.htmlMailing ListThird Party Advisory
https://security.gentoo.org/glsa/202202-03Third Party Advisory
https://security.gentoo.org/glsa/202208-14Third Party Advisory
https://www.debian.org/security/2021/dsa-5026Third Party Advisory
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