CVE-2021-24378

Autoptimize <= 2.7.7 - Unsafe File Upload to Cross-Site Scripting

2020-10-09 00:00
Marcin Węgłowski

Strategic Overview

Status
Patched in 2.7.8
Affected Plugin
Autoptimize
Affected Version
< 2.7.8
CVSS
4.8Medium
Weakness type
CWE-79 · Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
CVE
CVE-2021-24378
View all Autoptimize vulnerabilities

At a glance

CVE-2021-24378 is a medium-severity Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting') vulnerability in the Autoptimize WordPress plugin, affecting versions < 2.7.8. It carries a CVSS score of 4.8 (reachable over the network; low attack complexity). The issue is fixed in version 2.7.8; sites on affected versions should update now. Disclosed October 2020, reported by Marcin Węgłowski.

Vulnerability Overview

The Autoptimize WordPress plugin before 2.7.8 does not check for malicious files such as .html in the archive uploaded via the 'Import Settings' feature. As a result, it is possible for a high privilege user to upload a malicious file containing JavaScript code inside an archive which will execute when a victim visits index.html inside the plugin directory.

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 Autoptimize < 2.7.8 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 Autoptimize the fix is 2.7.8: builds < 2.7.8 are affected, anything from 2.7.8 onward is not.

Remediation

Update to version 2.7.8, or a newer patched version

How does WordSec protect against this?

The attempt arrives as an ordinary request to Autoptimize: WordSec's web application firewall inspects request payloads before WordPress loads them. None of that substitutes for the fix: Autoptimize 2.7.8 closes this, and updating the plugin is the step that ends it.

  • Firewall
  • Alerts

External References

https://www.cve.org/CVERecord?id=CVE-2021-24378https://www.wordfence.com/threat-intel/vulnerabilities/id/c95210ba-65f6-4bf8-8986-f537f1854d02https://nvd.nist.gov/vuln/detail/CVE-2021-24378

Related records

Vulnerability data © Defiant, Inc., provided under the Wordfence Intelligence T&C