Is CVE-2021-31806 in the CISA KEV catalog?

No. CVE-2021-31806 is not currently on the CISA Known Exploited Vulnerabilities list.

What is the CVSS severity of CVE-2021-31806?

CVE-2021-31806 has a CVSS v3 base score of 6.5 (MEDIUM).

What is the EPSS score for CVE-2021-31806?

CVE-2021-31806 has an EPSS score of 95.78% (100th percentile), estimating the probability of exploitation in the next 30 days.

How do I fix CVE-2021-31806?

Upgrade squid on debian 11 to 4.13-10 or later. Fixes are available for 3 affected products.

CVE & CISA-KEV Catalog

CVE-2021-31806

MEDIUMEPSS 100th pctl

6.5

CVSS v3

NVD

Description

An issue was discovered in Squid before 4.15 and 5.x before 5.0.6. Due to a memory-management bug, it is vulnerable to a Denial of Service attack (against all clients using the proxy) via HTTP Range request processing.

CWE-116

How to fix

Remediation Available

squidDebian

Fixed in:4.13-10CVE-2021-31806

squidUbuntu

Fixed in:3.5.27-1ubuntu1.11USN-4981-1

Fixed in:4.10-1ubuntu1.4USN-4981-1

squid3Ubuntu

Fixed in:3.5.27-1ubuntu1.11USN-4981-1

TridentStack Control can deploy fixes like this automatically across your Windows, macOS, and Linux fleet. See how it works

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 RequiredLow

User InteractionNone

ScopeUnchanged

Impact

ConfidentialityNone

IntegrityNone

AvailabilityHigh

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

Exploit Intelligence

95.78%probability of exploitation in 30 days

100thpercentile

Very high risk: more likely to be exploited than 100% of all known CVEs.

References

Patch2

Third-Party Advisory5

Other references2

Related Vulnerabilities

Other CWE-116 vulnerabilities, ordered by exploit likelihood. View all

CVE	Severity	CVSS	EPSS	Exploited	Fix
CVE-2024-38475	Critical	9.1	100%	KEV	Fix
CVE-2022-36446	Critical	9.8	96%	-	Fix
CVE-2022-30781	High	7.5	88%	-	Fix
CVE-2022-36099	Critical	9.9	76%	-	Fix
CVE-2022-36100	Critical	9.9	74%	-	Fix
CVE-2021-28662	Medium	6.5	72%	-	Fix

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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.