DOM XSS vulnerability in search dialogue (NC-SA-2017-007)

Summary

#DOM XSS vulnerability in search dialogue (NC-SA-2017-007) Risk level: Low CVSS v3 Base Score: 2.6 (AV:N/AC:H/PR:L/UI:R/S:U/C:L/I:N/A:N) CWE: Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting') (CWE-79)

#Description Inadequate escaping lead to XSS vulnerability in the search module. To be exploitable an user has to write or paste malicious content into the search dialogue.

#Affected Software

• Nextcloud Server < 11.0.3 (CVE-2017-0890)

#Action Taken The content is now properly escaped, furthermore for Nextcloud 12 we have hardened jQuery to prevent such CSP bypasses.

#Acknowledgements The Nextcloud team thanks the following people for their research and responsible disclosure of the above advisory:

• Ahsan Khan - Vulnerability discovery and disclosure.