CVE & CISA-KEV Catalog

CVE-2021-23999

HIGH
8.8
CVSS v3
NVD

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.

CWE-269Improper Privilege ManagementCWE-697

How to fix

Remediation Available
firefoxDebian
Fixed in:88.0-1CVE-2021-23999
firefoxUbuntu
Fixed in:88.0+build2-0ubuntu0.16.04.1USN-4926-1
Fixed in:88.0+build2-0ubuntu0.18.04.2USN-4926-1
Fixed in:88.0+build2-0ubuntu0.20.04.1USN-4926-1
thunderbirdUbuntu
Fixed in:1:78.11.0+build1-0ubuntu0.18.04.2USN-4995-2
Fixed in:1:78.11.0+build1-0ubuntu0.20.04.2USN-4995-1
DeveloperEditionWindows application
Affected:88.0Fixed in:88.0Mozilla
Mozilla Firefox (en-US)Windows application
Affected:88.0Fixed in:88.0Mozilla
Mozilla Firefox ESR (en-US)Windows application
Affected:78.10Fixed in:78.10Mozilla
Mozilla Thunderbird (en-US)Windows application
Affected:78.10Fixed in:78.10Mozilla

Remediation is compiled from vendor and distribution security advisories. Always confirm against the linked source for your exact version and platform.

CVSS v3 Vector

Exploitability

Attack VectorNetwork
Attack ComplexityLow
Privileges RequiredNone
User InteractionRequired
ScopeUnchanged

Impact

ConfidentialityHigh
IntegrityHigh
AvailabilityHigh

CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H

Exploit Intelligence

1.28%probability of exploitation in 30 days
66thpercentile

Moderate risk: more likely to be exploited than 66% of all known CVEs.

References

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Markdown

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This product uses NVD data but is not endorsed or certified by the NVD. EPSS scores courtesy of FIRST.org (https://www.first.org/epss). Source: CISA KEV Catalog. Data as of 2024-11-21.