CVE-2021-32708

Published Jun 24, 2021

Last updated a year ago

Overview

Description
Flysystem is an open source file storage library for PHP. The whitespace normalisation using in 1.x and 2.x removes any unicode whitespace. Under certain specific conditions this could potentially allow a malicious user to execute code remotely. The conditions are: A user is allowed to supply the path or filename of an uploaded file, the supplied path or filename is not checked against unicode chars, the supplied pathname checked against an extension deny-list, not an allow-list, the supplied path or filename contains a unicode whitespace char in the extension, the uploaded file is stored in a directory that allows PHP code to be executed. Given these conditions are met a user can upload and execute arbitrary code on the system under attack. The unicode whitespace removal has been replaced with a rejection (exception). For 1.x users, upgrade to 1.1.4. For 2.x users, upgrade to 2.1.1.
Source
security-advisories@github.com
NVD status
Modified

Risk scores

CVSS 3.1

Type
Primary
Base score
8.1
Impact score
5.9
Exploitability score
2.2
Vector string
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H
Severity
HIGH

CVSS 2.0

Type
Primary
Base score
9.3
Impact score
10
Exploitability score
8.6
Vector string
AV:N/AC:M/Au:N/C:C/I:C/A:C

Weaknesses

nvd@nist.gov
CWE-367
security-advisories@github.com
CWE-367

Social media

Hype score
Not currently trending

Configurations