CVE-2021-32708
Publication date 24 June 2021
Last updated 11 July 2025
Ubuntu priority
Cvss 3 Severity Score
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.
Status
| Package | Ubuntu Release | Status |
|---|---|---|
| php-league-flysystem | 26.04 LTS resolute |
Needs evaluation
|
| 24.04 LTS noble |
Needs evaluation
|
|
| 22.04 LTS jammy |
Needs evaluation
|
|
| 20.04 LTS focal | Not in release | |
| 18.04 LTS bionic | Not in release | |
| 16.04 LTS xenial |
Needs evaluation
|
|
| 14.04 LTS trusty | Not in release |
Severity score breakdown
CVSS version: CVSS v3.0
Base score
9.8 · Critical
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
References
Other references
- https://github.com/thephpleague/flysystem/commit/f3ad69181b8afed2c9edf7be5a2918144ff4ea32
- https://github.com/thephpleague/flysystem/commit/a3c694de9f7e844b76f9d1b61296ebf6e8d89d74
- https://github.com/thephpleague/flysystem/security/advisories/GHSA-9f46-5r25-5wfm
- https://packagist.org/packages/league/flysystem
- https://www.cve.org/CVERecord?id=CVE-2021-32708