CVE-2019-16520

All In One SEO Pack <= 3.2.6 - Stored Cross-Site Scripting

2019-10-16 00:00
Tobias Fink

Strategic Overview

Status
Patched in 3.2.7
Affected Plugin
All in One SEO – AI SEO Plugin to Boost SEO Rankings & Traffic (Schema, Local SEO, Sitemap & SEO Insights)
Affected Version
<= 3.2.6
CVSS
6.4Medium
Weakness type
CWE-79 · Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
CVE
CVE-2019-16520
View all All in One SEO – AI SEO Plugin to Boost SEO Rankings & Traffic (Schema, Local SEO, Sitemap & SEO Insights) vulnerabilities

At a glance

CVE-2019-16520 is a medium-severity Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting') vulnerability in the All in One SEO WordPress plugin, affecting versions <= 3.2.6. It carries a CVSS score of 6.4 (reachable over the network; low attack complexity). The issue is fixed in version 3.2.7; sites on affected versions should update now. Disclosed October 2019, reported by Tobias Fink.

Vulnerability Overview

The all-in-one-seo-pack plugin before 3.2.7 for WordPress (aka All in One SEO Pack) is susceptible to Stored XSS due to improper encoding of the SEO-specific description for posts provided by the plugin via unsafe placeholder replacement.

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 interaction from a victim user.

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

Reaching this weakness in All in One SEO <= 3.2.6 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 All in One SEO the fix is 3.2.7: builds <= 3.2.6 are affected, anything from 3.2.7 onward is not.

Remediation

Update to version 3.2.7, or a newer patched version

How does WordSec protect against this?

The attempt arrives as an ordinary request to All in One SEO: WordSec's web application firewall inspects request payloads before WordPress loads them. None of that substitutes for the fix: All in One SEO 3.2.7 closes this, and updating the plugin is the step that ends it.

  • Firewall
  • Alerts

External References

https://www.cve.org/CVERecord?id=CVE-2019-16520https://www.wordfence.com/threat-intel/vulnerabilities/id/02cf711b-69af-4869-9ebd-31c657be1bc3https://nvd.nist.gov/vuln/detail/CVE-2019-16520

Related records

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