CVE-2021-24508

Smash Balloon Social Post Feed <= 2.19.1 - Unauthenticated Stored Cross-Site Scripting

2021-08-16 00:00
dc11

Strategic Overview

Status
Patched in 2.19.2
Affected Plugin
Smash Balloon Social Post Feed – Simple Social Feeds for WordPress
Affected Version
< 2.19.2
CVSS
6.1Medium
Weakness type
CWE-79 · Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
CVE
CVE-2021-24508
View all Smash Balloon Social Post Feed – Simple Social Feeds for WordPress vulnerabilities

At a glance

CVE-2021-24508 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 < 2.19.2. 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 2.19.2; sites on affected versions should update now. Disclosed August 2021, reported by dc11.

Vulnerability Overview

The Smash Balloon Social Post Feed WordPress plugin before 2.19.2 does not sanitise or escape the feedID POST parameter in its feed_locator AJAX action (available to both authenticated and unauthenticated users) before outputting a truncated version of it in the admin dashboard, leading to an unauthenticated Stored Cross-Site Scripting issue which will be executed in the context of a logged in administrator.

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')

Reaching this weakness in Smash Balloon Social Post Feed < 2.19.2 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 Smash Balloon Social Post Feed the fix is 2.19.2: builds < 2.19.2 are affected, anything from 2.19.2 onward is not.

Remediation

Update to version 2.19.2, 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: Smash Balloon Social Post Feed 2.19.2 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-2021-24508https://www.wordfence.com/threat-intel/vulnerabilities/id/3a2c96a1-bbab-41ed-aafd-6a6f569242f3https://nvd.nist.gov/vuln/detail/CVE-2021-24508

Related records

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