GitHub Enterprise Server allows script injection via task list content

Summary

An attacker could inject malicious code into a user's browser session if they can create a task list item in an issue or pull request. This could happen to any user of GitHub Enterprise Server before version 3.20. To fix this, update to GitHub Enterprise Server 3.18.6 or 3.19.3 or later.

What to do

No fix is available yet. Check with your software vendor for updates.

Affected software

Vendor	Product	Affected versions	Fix available
github	enterprise_server	<= 3.18.6	–
github	enterprise_server	> 3.19.0 , <= 3.19.3	–

Original title

An improper neutralization of input vulnerability was identified in GitHub Enterprise Server that allowed DOM-based cross-site scripting via task list content. The task list content extraction logi...

Original description

An improper neutralization of input vulnerability was identified in GitHub Enterprise Server that allowed DOM-based cross-site scripting via task list content. The task list content extraction logic did not properly re-encode browser-decoded text nodes before rendering, allowing user-supplied HTML to be injected into the page. An authenticated attacker could craft malicious task list items in issues or pull requests to execute arbitrary scripts in the context of another user's browser session. This vulnerability affected all versions of GitHub Enterprise Server prior to 3.20 and was fixed in versions 3.18.6 and 3.19.3. This vulnerability was reported via the GitHub Bug Bounty program.

nvd CVSS4.0 7.4

Vulnerability type

CWE-79 Cross-site Scripting (XSS)