Google Fonts Typography <= 3.0.2 - Authenticated (Contributor+) Stored Cross-Site Scripting via blockType arguments
Strategic Overview
- Status
- Patched in 3.0.3
- Affected Plugin
- Fonts Plugin | Google Fonts, Adobe Fonts & Upload Fonts
- Affected Version
< 3.0.3- CVSS
- 5.4Medium
- Weakness type
- CWE-79 · Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
- CVE
CVE-2021-24637
At a glance
CVE-2021-24637 is a medium-severity Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting') vulnerability in the Fonts Plugin WordPress plugin, affecting versions < 3.0.3. 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 3.0.3; sites on affected versions should update now. Disclosed August 2021, reported by apple502j.
Vulnerability Overview
The Google Fonts Typography WordPress plugin before 3.0.3 does not escape and sanitize some of its block settings, allowing users with as role as low as Contributor to perform Stored Cross-Site Scripting attacks via blockType (combined with content), align, color, variant and fontID argument of a Gutenberg 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 Fonts Plugin < 3.0.3 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 Fonts Plugin the fix is 3.0.3: builds < 3.0.3 are affected, anything from 3.0.3 onward is not.
Remediation
Update to version 3.0.3, 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: Fonts Plugin 3.0.3 closes this, and updating the plugin is the step that ends it.
- Firewall
- Alerts
External References
Related records
Other vulnerabilities in Fonts Plugin | Google Fonts, Adobe Fonts & Upload Fonts
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