THREATPORT/VULNERABILITY/CVE-2021-32708
CRITICAL SEVERITY

CVE-2021-32708

Flysystem vulnerability

CVSS
9.8
EPSS
3.5%
EPSS pct
88th
Exploited
No known
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.
Affected vendor
Thephpleague
Affected product
Flysystem
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Weakness type (CWE)
  • CWE-367 — Time-of-check Time-of-use (TOCTOU) Race Condition
Published
2021-06-24

Risk analysis

Based on its CVSS vector, this vulnerability is exploitable over the network, low attack complexity, requiring no privileges, no user interaction. Successful exploitation leads to high impact to confidentiality, high impact to integrity, high impact to availability.

Its EPSS score of 3.5% reflects a lower probability of exploitation activity in the wild over the next 30 days, placing it above 88% of all scored CVEs.

Check your external exposure to CVE-2021-32708

  • Confirm whether Thephpleague Flysystem is running on any internet-facing host or subdomain.
  • Match discovered service fingerprints against the version affected by CVE-2021-32708.
  • Prioritise remediation if the asset is public, business-critical, or near authentication/payment flows.

How ThreatPort helps with CVE-2021-32708

ThreatPort's external attack surface scanner checks your internet-facing assets — agentlessly, from the outside in — for the exposed services and versions that CVE-2021-32708 affects, then prioritises the finding by real risk using CISA KEV and FIRST.org EPSS.

Run a free external exposure scan

Are you exposed to CVE-2021-32708?

Run an instant, non-intrusive external scan to check your attack surface for CVE-2021-32708.

Start free scan

No credit card. Agentless.

Related vulnerabilities

CRITICAL
CVE-2017-6640
Prime Data Center Network Manager vulnerability
CRITICAL
CVE-2014-8687
Business Nas Firmware vulnerability
CRITICAL
CVE-2016-3690
Jboss Enterprise Application Platform vulnerability