Tittle:
WordPress Plugin PrePost SEO <= 3.0 - Admin + Stored Cross-Site Scripting


References:
CVE-2023-2029

Author:
Taurus Omar 

Description:
The plugin does not properly sanitize some of its settings, which could allow high-privilege users to perform Stored Cross-Site Scripting (XSS) attacks even when the unfiltered_html capability is disallowed (for example in multisite setup)

Affects Plugins:
PrePost SEO - No known fix - plugin closed

Proof of Concept:

1. Add XSS payload to plugin's "Account API key" setting: "><iframe src="<svg onload=alert(4);>">

2. Save and see XSS exploit. 


Classification:
Type XSS 
OWASP top 10 A7: Cross-Site Scripting (XSS)
CWE-79

wpScan:
https://wpscan.com/vulnerability/4889ad5a-c8c4-4958-b176-64560490497b