High severity · published Jun 24, 2021
CVE-2021-23999
If a Blob URL was loaded through some unusual user interaction, it could have been loaded by the System Principal and granted additional privileges that should not be granted to…
8.8
CVSS
1.4%
EPSS
No
On KEV
Description
If a Blob URL was loaded through some unusual user interaction, it could have been loaded by the System Principal and granted additional privileges that should not be granted to web content. This vulnerability affects Firefox ESR < 78.10, Thunderbird < 78.10, and Firefox < 88.
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
Required
Confidentiality
High
Integrity
High
Availability
High
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)1.4% · higher than 72% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
FI
Firefox · Mozilla
before 88.0 · source: NVD
FE
Firefox Esr · Mozilla
before 78.10 · source: NVD
TH
Thunderbird · Mozilla
before 78.10 · source: NVD
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2021-23999
CVE.org
https://www.cve.org/CVERecord?id=CVE-2021-23999
Exploit
https://bugzilla.mozilla.org/show_bug.cgi?id=1691153
Release Notes
https://www.mozilla.org/security/advisories/mfsa2021-14/
Release Notes
https://www.mozilla.org/security/advisories/mfsa2021-15/
Release Notes
https://www.mozilla.org/security/advisories/mfsa2021-16/
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