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High severity · published Feb 26, 2021
CVE-2021-23978
Mozilla developers reported memory safety bugs present in Firefox 85 and Firefox ESR 78.7
8.8
CVSS
1.5%
EPSS
No
On KEV
Description
Mozilla developers reported memory safety bugs present in Firefox 85 and Firefox ESR 78.7. Some of these bugs showed evidence of memory corruption and we presume that with enough effort some of these could have been exploited to run arbitrary code. This vulnerability affects Firefox < 86, Thunderbird < 78.8, and Firefox ESR < 78.8.
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)1.5% · higher than 75% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
FI
Firefox · Mozilla
before 86.0 · source: NVD
DL
Debian Linux · Debian
9.0; 10.0 · source: NVD
FE
Firefox Esr · Mozilla
before 78.8 · source: NVD
TH
Thunderbird · Mozilla
before 78.8 · source: NVD
Affected product
FI
Firefox
Mozilla
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2021-23978
CVE.org
https://www.cve.org/CVERecord?id=CVE-2021-23978
Broken Link
https://bugzilla.mozilla.org/buglist.cgi?bug_id=786797%2C1682928%2C1687391%2C1687597
Mailing List
https://lists.debian.org/debian-lts-announce/2021/03/msg00000.html
Third Party Advisory
https://security.gentoo.org/glsa/202104-09
Third Party Advisory
https://security.gentoo.org/glsa/202104-10
Third Party Advisory
https://www.debian.org/security/2021/dsa-4866
Release Notes
https://www.mozilla.org/security/advisories/mfsa2021-07/
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