CVE-2021-24454

YOP Poll <= 6.2.7 - Unauthenticated Stored Cross-Site Scripting

2021-06-17 00:00
Toby Jackson

Strategic Overview

Status
Patched in 6.2.8
Affected Plugin
YOP Poll
Affected Version
<= 6.2.7
CVSS
6.1Medium
Weakness type
CWE-79 · Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
CVE
CVE-2021-24454
View all YOP Poll vulnerabilities

At a glance

CVE-2021-24454 is a medium-severity Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting') vulnerability in the YOP Poll WordPress plugin, affecting versions <= 6.2.7. It carries a CVSS score of 6.1 (reachable over the network; low attack complexity). Exploitation requires no authentication. The issue is fixed in version 6.2.8; sites on affected versions should update now. Disclosed June 2021, reported by Toby Jackson.

Vulnerability Overview

In the YOP Poll WordPress plugin before 6.2.8, when a pool is created with the options "Allow other answers", "Display other answers in the result list" and "Show results", it can lead to Stored Cross-Site Scripting issues as the 'Other' answer is not sanitised before being output in the page. The execution of the XSS payload depends on the 'Show results' option selected, which could be before or after sending the vote for example.

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

YOP Poll <= 6.2.7 carries this weakness at and, and reaching it takes no account at all. 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 YOP Poll the fix is 6.2.8: builds <= 6.2.7 are affected, anything from 6.2.8 onward is not.

Remediation

Update to version 6.2.8, or a newer patched version

How does WordSec protect against this?

Requests carrying this pattern arrive without a session, so nothing upstream of the firewall gets a chance to reject them: WordSec's web application firewall inspects request payloads before WordPress loads them. None of that substitutes for the fix: YOP Poll 6.2.8 closes this, and updating the plugin is the step that ends it.

  • Firewall
  • Login Security
  • Alerts

External References

https://www.cve.org/CVERecord?id=CVE-2021-24454https://www.wordfence.com/threat-intel/vulnerabilities/id/5df238dd-6269-4ee0-a0f4-12bdb74f74e8https://nvd.nist.gov/vuln/detail/CVE-2021-24454

Related records

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