GHSL-2021-1006: Copy-paste XSS in vditor text editor - CVE-2021-32855

Coordinated Disclosure Timeline

• 2021-09-15: Report sent to os@b3log.org
• 2021-09-17: Emails get bounced back. Request contact publicly
• 2021-09-21: Report sent to 845765@qq.com
• 2021-09-22: Issue collision with a different security researcher
• 2021-09-22: Issues fixed in 1b2382d

Summary

Copy-paste XSS in vditor text editor

Product

vditor

Tested Version

v3.8.5

Details

Issue: Copy-paste XSS in vditor (GHSL-2021-1006)

The vditor text editor is vulnerable to copy-paste cross-site scripting (XSS). For this particular type of XSS, the victim needs to be fooled into copying a malicious payload into the text editor.

Proof of concept (tested on Chrome):

• Open this page: cdn.sekurak.pl/copy-paste/playground.html
• Paste the following code into “HTML Input”

  <img src="foo" onload="alert(1)" onerror="alert(2)"/>
  

• Click “Copy as HTML”
• Open https://b3log.org/vditor/demo/option-mode.html
• Paste into the text editor.

Note: This issue was found using the following CodeQL query

Impact

This issue may lead to XSS with user interaction

CVE

• CVE-2021-32855

Credit

This issue was discovered by GHSL team member @erik-krogh (Erik Kristensen) using the CodeQL query contributed by @bananabr (Daniel Santos).

Contact

You can contact the GHSL team at securitylab@github.com, please include a reference to GHSL-2021-1006 in any communication regarding this issue.