CVE-2021-24517

Stop Spammers Security <= 2021.17 - Authenticated (Admin+) Stored Cross-Site Scripting

2021-08-09 00:00
swapnil subhash bodekar

Strategic Overview

Status
Patched in 2021.18
Affected Plugin
Stop Spammers Classic
Affected Version
< 2021.18
CVSS
4.8Medium
Weakness type
CWE-79 · Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
CVE
CVE-2021-24517
View all Stop Spammers Classic vulnerabilities

At a glance

CVE-2021-24517 is a medium-severity Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting') vulnerability in the Stop Spammers Classic WordPress plugin, affecting versions < 2021.18. It carries a CVSS score of 4.8 (reachable over the network; low attack complexity). Exploitation requires an authenticated account at Admin level or above. The issue is fixed in version 2021.18; sites on affected versions should update now. Disclosed August 2021, reported by swapnil subhash bodekar.

Vulnerability Overview

The Stop Spammers Security | Block Spam Users, Comments, Forms WordPress plugin before 2021.18 does not escape some of its settings, allowing high privilege users such as admin to set Cross-Site Scripting payloads in them even when the unfiltered_html capability is disallowed

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 Stop Spammers Classic < 2021.18 takes an account at Admin 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 Stop Spammers Classic the fix is 2021.18: builds < 2021.18 are affected, anything from 2021.18 onward is not.

Remediation

Update to version 2021.18, or a newer patched version

How does WordSec protect against this?

An attacker needs Admin 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: Stop Spammers Classic 2021.18 closes this, and updating the plugin is the step that ends it.

  • Firewall
  • Alerts

External References

https://www.cve.org/CVERecord?id=CVE-2021-24517https://www.wordfence.com/threat-intel/vulnerabilities/id/1bf805fc-4b27-47c4-b24e-79158cffaac4https://nvd.nist.gov/vuln/detail/CVE-2021-24517

Related records

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