CVE-2021-24918

Smash Balloon Social Post Feed <= 4.0 - Arbitrary Plugin Settings Update to Stored Cross-Site Scripting

2021-10-29 00:00
Marc-Alexandre Montpas

Strategic Overview

Status
Patched in 4.0.1
Affected Plugin
Smash Balloon Social Post Feed – Simple Social Feeds for WordPress
Affected Version
< 4.0.1
CVSS
5.4Medium
Weakness type
CWE-79 · Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
CVE
CVE-2021-24918
View all Smash Balloon Social Post Feed – Simple Social Feeds for WordPress vulnerabilities

At a glance

CVE-2021-24918 is a medium-severity Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting') vulnerability in the Smash Balloon Social Post Feed WordPress plugin, affecting versions < 4.0.1. It carries a CVSS score of 5.4 (reachable over the network; low attack complexity). The issue is fixed in version 4.0.1; sites on affected versions should update now. Disclosed October 2021, reported by Marc-Alexandre Montpas.

Vulnerability Overview

The Smash Balloon Social Post Feed WordPress plugin before 4.0.1 did not have any privilege or nonce validation before saving the plugin's setting. As a result, any logged-in user on a vulnerable site could update the settings and store rogue JavaScript on each of its posts and pages.

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 Smash Balloon Social Post Feed < 4.0.1 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 Smash Balloon Social Post Feed the fix is 4.0.1: builds < 4.0.1 are affected, anything from 4.0.1 onward is not.

Remediation

Update to version 4.0.1, or a newer patched version

How does WordSec protect against this?

The attempt arrives as an ordinary request to Smash Balloon Social Post Feed: WordSec's web application firewall inspects request payloads before WordPress loads them. None of that substitutes for the fix: Smash Balloon Social Post Feed 4.0.1 closes this, and updating the plugin is the step that ends it.

  • Firewall
  • Alerts

External References

https://www.cve.org/CVERecord?id=CVE-2021-24918https://www.wordfence.com/threat-intel/vulnerabilities/id/74fac72d-6f16-475c-bc80-e77968dd23adhttps://nvd.nist.gov/vuln/detail/CVE-2021-24918

Related records

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