Self-XSS prevention mechanism bypass in Mozilla Firefox - CVE-2017-7840
Published: November 15, 2017
Vulnerability identifier: #VU9327
CSH Severity: Low
CVSS v4.0: CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:A/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N/E:U/U:Clear
CVE-ID: CVE-2017-7840
CWE-ID: CWE-20
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vendor: Mozilla
Affected software:
Mozilla Firefox
Mozilla Firefox
Detailed vulnerability description
The vulnerability allows a remote attacker to bypass Self-XSS prevention mechanism.
JavaScript can be injected into an exported bookmarks file by placing JavaScript code into user-supplied tags in saved bookmarks. If the resulting exported HTML file is later opened in a browser this JavaScript will be executed. This could be used in social engineering and self-cross-site-scripting (self-XSS) attacks if users were convinced to add malicious tags to bookmarks, export them, and then open the resulting file.
How to mitigate CVE-2017-7840
Update to version Firefox 57.