CVE-2021-34639

WordPress Download Manager <= 3.1.24 - Authenticated File Upload

2021-07-29 00:00
Ram

Strategic Overview

Status
Patched in 3.1.25
Affected Plugin
Download Manager
Affected Version
<= 3.1.24
CVSS
7.5High
Weakness type
CWE-434 · Unrestricted Upload of File with Dangerous Type
CVE
CVE-2021-34639
View all Download Manager vulnerabilities

At a glance

CVE-2021-34639 is a high-severity Unrestricted Upload of File with Dangerous Type vulnerability in the Download Manager WordPress plugin, affecting versions <= 3.1.24. It carries a CVSS score of 7.5 (reachable over the network; high confidentiality, integrity, availability impact). Exploitation requires an authenticated account. The issue is fixed in version 3.1.25; sites on affected versions should update now. Disclosed July 2021, reported by Ram.

Vulnerability Overview

Authenticated File Upload in WordPress Download Manager <= 3.1.24 allows authenticated (Author+) users to upload files with a double extension, e.g. "payload.php.png" which is executable in some configurations. This issue affects: WordPress Download Manager version 3.1.24 and prior versions.

Technical Analysis

The vector marks this flaw as remotely reachable over the network, and no interaction from a victim user. A successful exploit has high impact on confidentiality, integrity, availability — full site compromise territory.

CWE-434: Unrestricted Upload of File with Dangerous Type

Reaching this weakness in Download Manager <= 3.1.24 takes any authenticated account. An unrestricted file upload lets a caller store a file whose type or destination the application does not properly constrain.

If an uploaded file lands anywhere the server will execute, the flaw becomes remote code execution and the site should be treated as fully compromised. For Download Manager the fix is 3.1.25: builds <= 3.1.24 are affected, anything from 3.1.25 onward is not.

Remediation

Update to version 3.1.25, or a newer patched version

How does WordSec protect against this?

The attempt arrives as an ordinary request to Download Manager: WordSec's web application firewall inspects request payloads before WordPress loads them. Classes like this one can leave something behind, so the staged malware scanner is the second half: it looks for dropped files and modified code rather than for the request that created them. None of that substitutes for the fix: Download Manager 3.1.25 closes this, and updating the plugin is the step that ends it.

  • Firewall
  • Scanner
  • Alerts

External References

https://www.cve.org/CVERecord?id=CVE-2021-34639https://www.wordfence.com/threat-intel/vulnerabilities/id/2cde1f4d-0212-48b1-a0ef-ba923c37ab50https://nvd.nist.gov/vuln/detail/CVE-2021-34639

Related records

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