CVE-2021-20270

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.

How to fix CVE-2021-20270

To remediate CVE-2021-20270, upgrade the affected package to a fixed version below.

• Alpine/py3-pygments—upgrade to 2.7.4-r0 or later
• —upgrade to 1:1.35.2-1 or later
• —upgrade to 1:1.27.7-1~deb9u8 or later
• —upgrade to 1:1.31.14-1~deb10u1 or later
• —upgrade to 2.7.1+dfsg-2 or later
• —upgrade to 2.2.0+dfsg-1+deb9u1 or later
• —upgrade to 2.3.1+dfsg-1+deb10u1 or later
• —upgrade to 2.7.4 or later
• —upgrade to 2.7.4 or later

Is CVE-2021-20270 being exploited?

Low — EPSS is 0.2%, meaning exploitation activity has not been observed at scale.

Affected packages (9)

• from 0, < 2.7.4-r0
• from 0, < 1:1.35.2-1
• from 0, < 1:1.27.7-1~deb9u8
• from 0, < 1:1.31.14-1~deb10u1
• from 0, < 2.7.1+dfsg-2
• from 0, < 2.2.0+dfsg-1+deb9u1
• from 0, < 2.3.1+dfsg-1+deb10u1
• >= 1.5, < 2.7.4
• >= 1.5, < 2.7.4

CVSS scores

References (12)

• ADVISORYgithub.com/advisories/GHSA-9w8r-397f-prfh
• ADVISORYnvd.nist.gov/vuln/detail/CVE-2021-20270
• ADVISORYsecurity.alpinelinux.org/vuln/CVE-2021-20270
• ADVISORYsecurity-tracker.debian.org/tracker/CVE-2021-20270
• PATCH