Transposh WordPress Translation 1.0.7 Cross Site Scripting

RCE Security Advisory
https://www.rcesecurity.com

1. ADVISORY INFORMATION
   =======================
   Product: Transposh WordPress Translation
   Vendor URL: https://wordpress.org/plugins/transposh-translation-filter-for-wordpress/
   Type: Cross-Site Scripting [CWE-79]
   Date found: 2021-08-19
   Date published: 2022-07-22
   CVSSv3 Score: 4.7 (CVSS:3.0/AV:N/AC:L/PR:N/UI:R/S:C/C:N/I:L/A:N)
   CVE: CVE-2021-24910

2. CREDITS
   ==========
   This vulnerability was discovered and researched by Julien Ahrens from
   RCE Security.

3. VERSIONS AFFECTED
   ====================
   Transposh WordPress Translation 1.0.7 and below

4. INTRODUCTION
   ===============
   Transposh translation filter for WordPress offers a unique approach to blog
   translation. It allows your blog to combine automatic translation with human
   translation aided by your users with an easy to use in-context interface.

(from the vendor’s homepage)

5. VULNERABILITY DETAILS
   ========================
   The plugin’s ajax action “tp_tp” is vulnerable to an unauthenticated/authenticated
   reflected Cross-Site Scripting vulnerability when user-supplied input to the HTTP
   GET parameter “q” is processed by the web application. Since the application does
   not properly validate and sanitize this parameter, it is possible to place
   arbitrary script code onto the same page.

This offers a wide range of possible attacks such as redirecting the user to a
malicious page, spoofing content on the page or attacking the browser and its
plugins. Since all session-relevant cookies are protected by HTTPOnly, it is not
possible to hijack sessions.

6. PROOF OF CONCEPT
   ===================
   The following PoC triggers a JavaScript alert:

http://[host]/wp-admin/admin-ajax.php?action=tp_tp&e=g&m=s&tl=en&q=<img%20src%3dx%20onerror%3dalert(document.cookie)>

7. SOLUTION
   ===========
   Update to Transposh 1.0.8.1

8. REPORT TIMELINE
   ==================
   2021-08-19: Discovery of the vulnerability
   2021-08-20: Contacted the vendor via their contact form
   2021-08-20: Vendor response
   2021-08-20: Sent all the PoC exploits
   2021-08-20: Vendor acknowledges the issues
   2021-09-14: Requested status update from vendor
   2021-10-07: No response from vendor, requested status update again
   2021-10-25: CVE requested from WPScan (CNA)
   2021-10-27: WPScan assigns CVE-2021-24910
   2022-02-22: Vendor releases 1.0.8 which fixes this vulnerability
   2022-07-22: Public disclosure

9. REFERENCES
   =============
   https://github.com/MrTuxracer/advisories
   https://transposh.org/version-1-0-8-thanks-julien/