CVE Vulnerabilities

CVE-2021-3828

Inefficient Regular Expression Complexity

Published: Sep 27, 2021 | Modified: Nov 21, 2024
CVSS 3.x
7.5
HIGH
Source:
NVD
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
CVSS 2.x
5 MEDIUM
AV:N/AC:L/Au:N/C:N/I:N/A:P
RedHat/V2
RedHat/V3
Ubuntu
MEDIUM

nltk is vulnerable to Inefficient Regular Expression Complexity

Weakness

The product uses a regular expression with an inefficient, possibly exponential worst-case computational complexity that consumes excessive CPU cycles.

Affected Software

Name Vendor Start Version End Version
Nltk Nltk * 3.6.3 (including)
Nltk Ubuntu bionic *
Nltk Ubuntu devel *
Nltk Ubuntu esm-apps/bionic *
Nltk Ubuntu esm-apps/focal *
Nltk Ubuntu esm-apps/xenial *
Nltk Ubuntu focal *
Nltk Ubuntu hirsute *
Nltk Ubuntu impish *
Nltk Ubuntu jammy *
Nltk Ubuntu kinetic *
Nltk Ubuntu lunar *
Nltk Ubuntu mantic *
Nltk Ubuntu noble *
Nltk Ubuntu oracular *
Nltk Ubuntu trusty *
Nltk Ubuntu upstream *
Nltk Ubuntu xenial *

Extended Description

	  Attackers can create crafted inputs that
	  intentionally cause the regular expression to use
	  excessive backtracking in a way that causes the CPU
	  consumption to spike.

Potential Mitigations

References