Is CVE-2021-23956 in the CISA KEV catalog?

No. CVE-2021-23956 is not currently on the CISA Known Exploited Vulnerabilities list.

What is the CVSS severity of CVE-2021-23956?

CVE-2021-23956 has a CVSS v3 base score of 6.5 (MEDIUM).

What is the EPSS score for CVE-2021-23956?

CVE-2021-23956 has an EPSS score of 0.99% (58th percentile), estimating the probability of exploitation in the next 30 days.

How do I fix CVE-2021-23956?

Upgrade firefox on debian unstable to 85.0-1 or later. Fixes are available for 4 affected products.

CVE & CISA-KEV Catalog

CVE-2021-23956

MEDIUM

6.5

CVSS v3

NVD

Description

An ambiguous file picker design could have confused users who intended to select and upload a single file into uploading a whole directory. This was addressed by adding a new prompt. This vulnerability affects Firefox < 85.

How to fix

Remediation Available

firefoxDebian

Fixed in:85.0-1CVE-2021-23956

firefoxUbuntu

Fixed in:85.0+build1-0ubuntu0.16.04.1USN-4717-1

Fixed in:85.0+build1-0ubuntu0.18.04.1USN-4717-1

Fixed in:85.0+build1-0ubuntu0.20.04.1USN-4717-1

DeveloperEditionWindows application

Affected:85.0Fixed in:85.0Mozilla

Mozilla Firefox (en-US)Windows application

Affected:85.0Fixed in:85.0Mozilla

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

IntegrityNone

AvailabilityNone

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

Exploit Intelligence

0.99%probability of exploitation in 30 days

58thpercentile

Moderate risk: more likely to be exploited than 58% of all known CVEs.

References

Patch1

bugzilla.mozilla.org

Vendor Advisory1

mozilla.org

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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.