CVE-2020-36750

EWWW Image Optimizer <= 5.8.1 - Cross-Site Request Forgery Bypass

2020-09-06 00:00
Jerome Bruandet

Strategic Overview

Status
Patched in 5.9
Affected Plugin
EWWW Image Optimizer
Affected Version
<= 5.8.1
CVSS
4.3Medium
Weakness type
CWE-352 · Cross-Site Request Forgery (CSRF)
CVE
CVE-2020-36750
View all EWWW Image Optimizer vulnerabilities

At a glance

CVE-2020-36750 is a medium-severity Cross-Site Request Forgery (CSRF) vulnerability in the EWWW Image Optimizer WordPress plugin, affecting versions <= 5.8.1. It carries a CVSS score of 4.3 (reachable over the network; low attack complexity). Exploitation requires no authentication. The issue is fixed in version 5.9; sites on affected versions should update now. Disclosed September 2020, reported by Jerome Bruandet.

Vulnerability Overview

The EWWW Image Optimizer plugin for WordPress is vulnerable to Cross-Site Request Forgery in versions up to, and including, 5.8.1. This is due to missing or incorrect nonce validation on the ewww_ngg_bulk_init() function. This makes it possible for unauthenticated attackers to perform bulk image optimization via a forged request granted they can trick a site administrator into performing an action such as clicking on a link.

Technical Analysis

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

CWE-352: Cross-Site Request Forgery (CSRF)

EWWW Image Optimizer <= 5.8.1 carries this weakness at ewww_ngg_bulk_init(), and reaching it takes a caller who can reach the endpoint. Cross-site request forgery abuses the fact that browsers attach a victim's cookies to any request, so a state-changing action that only checks who you are, not whether you meant to act, can be triggered from another site.

An attacker who gets a logged-in user to load a crafted page can perform that action as them, with the impact scaling to whatever the victim's role is allowed to do. For EWWW Image Optimizer the fix is 5.9: builds <= 5.8.1 are affected, anything from 5.9 onward is not.

Remediation

Update to version 5.9, or a newer patched version

How does WordSec protect against this?

The attempt arrives as an ordinary request to EWWW Image Optimizer: WordSec's web application firewall inspects request payloads before WordPress loads them. None of that substitutes for the fix: EWWW Image Optimizer 5.9 closes this, and updating the plugin is the step that ends it.

  • Firewall
  • Alerts

External References

https://www.cve.org/CVERecord?id=CVE-2020-36750https://www.wordfence.com/threat-intel/vulnerabilities/id/8ef33e3c-187a-45d9-9dac-0895dce34216https://nvd.nist.gov/vuln/detail/CVE-2020-36750

Related records

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