CVE-2021-24856

Shared Files – Easy Download Manager and File Sharing Plugin with Frontend File Upload <= 1.6.60 - Cross-Site Scripting

2021-10-18 00:00
Kévin Mosbahi (Mika)

Strategic Overview

Status
Patched in 1.6.61
Affected Plugin
Shared Files – File Upload & Download Manager
Affected Version
< 1.6.61
CVSS
4.8Medium
Weakness type
CWE-79 · Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
CVE
CVE-2021-24856
View all Shared Files – File Upload & Download Manager vulnerabilities

At a glance

CVE-2021-24856 is a medium-severity Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting') vulnerability in the Shared Files WordPress plugin, affecting versions < 1.6.61. It carries a CVSS score of 4.8 (reachable over the network; low attack complexity). The issue is fixed in version 1.6.61; sites on affected versions should update now. Disclosed October 2021, reported by Kévin Mosbahi (Mika).

Vulnerability Overview

The Shared Files WordPress plugin before 1.6.61 does not sanitise and escape the Download Counter Text settings, which could allow high privilege users to perform Cross-Site Scripting attacks even when the unfiltered_html capability is disallowed

Technical Analysis

The vector marks this flaw as remotely reachable over the network, with low attack complexity — no special timing or configuration is needed.

CWE-79: Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')

Reaching this weakness in Shared Files < 1.6.61 takes a caller who can reach the endpoint. Cross-site scripting happens when input from a request is written into a page without being escaped for the context it lands in, so the browser parses attacker-supplied text as markup or script.

Injected script runs with the privileges of whoever views the affected page, which is how these flaws turn into administrator session theft, silent account creation or persistent backdoors in page content. For Shared Files the fix is 1.6.61: builds < 1.6.61 are affected, anything from 1.6.61 onward is not.

Remediation

Update to version 1.6.61, or a newer patched version

How does WordSec protect against this?

The attempt arrives as an ordinary request to Shared Files: WordSec's web application firewall inspects request payloads before WordPress loads them. None of that substitutes for the fix: Shared Files 1.6.61 closes this, and updating the plugin is the step that ends it.

  • Firewall
  • Alerts

External References

https://www.cve.org/CVERecord?id=CVE-2021-24856https://www.wordfence.com/threat-intel/vulnerabilities/id/97e9037e-7d7a-4dad-bce1-0211822c04c1https://nvd.nist.gov/vuln/detail/CVE-2021-24856

Related records

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