Medium severity · published Dec 8, 2021
CVE-2021-43542
Using XMLHttpRequest, an attacker could have identified installed applications by probing error messages for loading external protocols
6.5
CVSS
1.8%
EPSS
No
On KEV
Description
Using XMLHttpRequest, an attacker could have identified installed applications by probing error messages for loading external protocols. This vulnerability affects Thunderbird < 91.4.0, Firefox ESR < 91.4.0, and Firefox < 95.
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
Required
Confidentiality
High
Integrity
None
Availability
None
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)1.8% · higher than 79% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
FI
Firefox · Mozilla
before 95.0 · source: NVD
DL
Debian Linux · Debian
9.0; 10.0; 11.0 · source: NVD
FE
Firefox Esr · Mozilla
before 91.4.0 · source: NVD
TH
Thunderbird · Mozilla
before 91.4.0 · source: NVD
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2021-43542
CVE.org
https://www.cve.org/CVERecord?id=CVE-2021-43542
Issue Tracking
https://bugzilla.mozilla.org/show_bug.cgi?id=1723281
Mailing List
https://lists.debian.org/debian-lts-announce/2021/12/msg00030.html
Mailing List
https://lists.debian.org/debian-lts-announce/2022/01/msg00001.html
Third Party Advisory
https://security.gentoo.org/glsa/202202-03
Third Party Advisory
https://security.gentoo.org/glsa/202208-14
Third Party Advisory
https://www.debian.org/security/2021/dsa-5026
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