Medium severity · published Feb 26, 2021
CVE-2021-23953
If a user clicked into a specifically crafted PDF, the PDF reader could be confused into leaking cross-origin information, when said information is served as chunked data
4.3
CVSS
1.1%
EPSS
No
On KEV
Description
If a user clicked into a specifically crafted PDF, the PDF reader could be confused into leaking cross-origin information, when said information is served as chunked data. This vulnerability affects Firefox < 85, Thunderbird < 78.7, and Firefox ESR < 78.7.
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:N/A:N
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
Required
Confidentiality
Low
Integrity
None
Availability
None
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)1.1% · higher than 64% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
FI
Firefox · Mozilla
before 85.0 · source: NVD
FE
Firefox Esr · Mozilla
before 78.7 · source: NVD
TH
Thunderbird · Mozilla
before 78.7 · source: NVD
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2021-23953
CVE.org
https://www.cve.org/CVERecord?id=CVE-2021-23953
Issue Tracking
https://bugzilla.mozilla.org/show_bug.cgi?id=1683940
Release Notes
https://www.mozilla.org/security/advisories/mfsa2021-03/
Release Notes
https://www.mozilla.org/security/advisories/mfsa2021-04/
Release Notes
https://www.mozilla.org/security/advisories/mfsa2021-05/
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