CVE-2021-32708

HIGH
Published Jun 24, 20215y ago · Modified Jun 17, 20262w ago
8.1 CVSS 3.1
High
Find Similar
Published Jun 24, 2021 5y ago
Last Modified Jun 17, 2026 2w ago

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.

CVSS Details

Base Score
8.1
Exploitability
2.2
Impact
5.9
Vector string
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H
Attack Vector Network
Attack Complexity High
Privileges Required None
User Interaction None
Scope Unchanged
Confidentiality High
Integrity High
Availability High

Threat Intelligence

No active exploitation signals — not in CISA KEV and no EPSS score yet.

Exploit & Patch Status
No Known Exploit
Patch Available

Weaknesses 1

CWE-367

Affected Products 4

VendorProductVersionRange
thephpleagueflysystem*≥1.0.0  –  <1.1.4
thephpleagueflysystem*≥2.0.0  –  <2.1.1
fedoraprojectfedora33any
fedoraprojectfedora34any

References 6

  • github.com https://github.com/thephpleague/flysystem/commit/a3c694de9f7e844b76f9d1b61296ebf6e8d89d74
    PatchThird Party Advisory
  • github.com https://github.com/thephpleague/flysystem/commit/f3ad69181b8afed2c9edf7be5a2918144ff4ea32
    PatchThird Party Advisory
  • github.com https://github.com/thephpleague/flysystem/security/advisories/GHSA-9f46-5r25-5wfm
    PatchThird Party Advisory
  • lists.fedoraproject.org https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/NWPTENBYKI2IG47GI4DHAACLNRLTWUR5/
  • lists.fedoraproject.org https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/RNZSWK4GOMJOOHKLZEOE5AQSLC4DNCRZ/
  • packagist.org https://packagist.org/packages/league/flysystem
    ProductThird Party Advisory

Remediation

  • github.com https://github.com/thephpleague/flysystem/commit/a3c694de9f7e844b76f9d1b61296ebf6e8d89d74
    PatchThird Party Advisory
  • github.com https://github.com/thephpleague/flysystem/commit/f3ad69181b8afed2c9edf7be5a2918144ff4ea32
    PatchThird Party Advisory
  • github.com https://github.com/thephpleague/flysystem/security/advisories/GHSA-9f46-5r25-5wfm
    PatchThird Party Advisory