Is CVE-2021-20270 in the CISA KEV catalog?

No. CVE-2021-20270 is not currently on the CISA Known Exploited Vulnerabilities list.

What is the CVSS severity of CVE-2021-20270?

CVE-2021-20270 has a CVSS v3 base score of 7.5 (HIGH).

What is the EPSS score for CVE-2021-20270?

CVE-2021-20270 has an EPSS score of 2.71% (84th percentile), estimating the probability of exploitation in the next 30 days.

How do I fix CVE-2021-20270?

Upgrade mediawiki on debian 11 to 1:1.35.2-1 or later. Fixes are available for 4 affected products.

CVE & CISA-KEV Catalog

CVE-2021-20270

HIGHEPSS 84th pctl

7.5

CVSS v3

NVD

Description

An infinite loop in SMLLexer in Pygments versions 1.5 to 2.7.3 may lead to denial of service when performing syntax highlighting of a Standard ML (SML) source file, as demonstrated by input that only contains the "exception" keyword.

CWE-835

How to fix

Remediation Available

mediawikiDebian

Fixed in:1:1.35.2-1CVE-2021-20270

pygmentsUbuntu

Fixed in:1.6+dfsg-1ubuntu1.1+esm1USN-4897-2

Fixed in:2.1+dfsg-1ubuntu0.1USN-4885-1

Fixed in:2.2.0+dfsg-1ubuntu0.1USN-4885-1

Fixed in:2.3.1+dfsg-1ubuntu2.1USN-4885-1

python-pygmentsUbuntu

Fixed in:1.6+dfsg-1ubuntu1.1+esm1USN-4897-2

Fixed in:2.1+dfsg-1ubuntu0.1USN-4885-1

Fixed in:2.2.0+dfsg-1ubuntu0.1USN-4885-1

Fixed in:2.3.1+dfsg-1ubuntu2.1USN-4885-1

python3-pygmentsUbuntu

Fixed in:1.6+dfsg-1ubuntu1.1+esm1USN-4897-2

Fixed in:2.1+dfsg-1ubuntu0.1USN-4885-1

Fixed in:2.2.0+dfsg-1ubuntu0.1USN-4885-1

Fixed in:2.3.1+dfsg-1ubuntu2.1USN-4885-1

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 InteractionNone

ScopeUnchanged

Impact

ConfidentialityNone

IntegrityNone

AvailabilityHigh

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

Exploit Intelligence

2.71%probability of exploitation in 30 days

84thpercentile

Elevated risk: more likely to be exploited than 84% of all known CVEs.

References

Patch1

bugzilla.redhat.com

Third-Party Advisory4

Related Vulnerabilities

Other CWE-835 vulnerabilities, ordered by exploit likelihood. View all

CVE	Severity	CVSS	EPSS	Exploited	Fix
CVE-2020-13935	High	7.5	88%	-	Fix
CVE-2020-36227	High	7.5	78%	-	Fix
CVE-2022-0778	High	7.5	71%	-	Fix
CVE-2019-14241	High	7.5	70%	-	-
CVE-2017-16944	High	7.5	63%	-	Fix
CVE-2024-20353	High	8.6	63%	KEV	-

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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.