Cyber Resilience

CVE-2021-20270

HighDDoS

Published: 23 March 2021

Published
23 March 2021
Modified
21 November 2024
KEV Added
—
Patch
—
CVSS Score v3.1 7.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
EPSS Score 0.0022 45.0th percentile
Risk Priority 15 60% EPSS · 20% KEV · 20% CVSS

Summary

CVE-2021-20270 is a high-severity Infinite Loop (CWE-835) vulnerability in Redhat Openshift Container Platform. Its CVSS base score is 7.5 (High).

Operationally, ranked at the 45.0th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.

This vulnerability is AI-related — categorised as Machine Learning Libraries.

EU & UK References

Vulnerability details

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(s)
CWE-835

AI Security AnalysisAI

AI Category
Machine Learning Libraries
Risk Domain
N/A
OWASP Top 10 for LLMs 2025
None mapped
Classification Reason
Matched keywords: ml

Related Threats

Affected Assets

pygments
pygments
1.5 — 2.7.3
redhat
openshift container platform
3.11, 4.0
redhat
openstack platform
10.0
redhat
software collections
all versions
redhat
enterprise linux
7.0, 8.0
fedoraproject
fedora
33
debian
debian linux
10.0, 9.0

Mitigating Controls

Likely Mitigating Controls AI

Per-CVE control mapping for this CVE has not run yet; the list below is derived from the weakness types (CWEs) cited in the NVD entry.

CP-7 Alternate Processing Site
addresses: CWE-835

Enables transfer to alternate site if an infinite loop at the primary renders processing unavailable.

SC-5 Denial-of-service Protection
addresses: CWE-835

Detects and mitigates infinite loops that produce sustained resource consumption.

References