CVE-2021-24659

PostX - Gutenberg Blocks for Post Grid <= 2.4.9 - Authenticated (Contributor+) Stored Cross-Site Scripting

2021-08-26 00:00
apple502j

Strategic Overview

Status
Patched in 2.4.10
Affected Plugin
Post Grid Gutenberg Blocks – PostX
Affected Version
< 2.4.10
CVSS
5.4Medium
Weakness type
CWE-79 · Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
CVE
CVE-2021-24659
View all Post Grid Gutenberg Blocks – PostX vulnerabilities

At a glance

CVE-2021-24659 is a medium-severity Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting') vulnerability in the Post Grid Gutenberg Blocks WordPress plugin, affecting versions < 2.4.10. It carries a CVSS score of 5.4 (reachable over the network; low attack complexity). Exploitation requires an authenticated account at Contributor level or above. The issue is fixed in version 2.4.10; sites on affected versions should update now. Disclosed August 2021, reported by apple502j.

Vulnerability Overview

The PostX – Gutenberg Blocks for Post Grid WordPress plugin before 2.4.10 allows users with a role as low as Contributor to perform Stored Cross-Site Scripting attacks via the plugin's block.

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 Post Grid Gutenberg Blocks < 2.4.10 takes an account at Contributor level or above. 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 Post Grid Gutenberg Blocks the fix is 2.4.10: builds < 2.4.10 are affected, anything from 2.4.10 onward is not.

Remediation

Update to version 2.4.10, or a newer patched version

How does WordSec protect against this?

An attacker needs Contributor access first, so the firewall sees the attempt as traffic from a logged-in account: WordSec's web application firewall inspects request payloads before WordPress loads them. None of that substitutes for the fix: Post Grid Gutenberg Blocks 2.4.10 closes this, and updating the plugin is the step that ends it.

  • Firewall
  • Alerts

External References

https://www.cve.org/CVERecord?id=CVE-2021-24659https://www.wordfence.com/threat-intel/vulnerabilities/id/52b1d515-4965-4ab9-80dd-526b4ebeb3a9https://nvd.nist.gov/vuln/detail/CVE-2021-24659

Related records

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