Spoofing attack with modal dialogs on non-e10s installations in Mozilla Firefox - CVE-2017-7815

Vulnerability identifier: #VU8626

CSH Severity: Medium

CVSS v4.0: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N/E:U/U:Green

CVE-ID: CVE-2017-7815

CWE-ID: CWE-451

Exploitation vector: Remote access

Exploit availability: No public exploit available

Vendor: Mozilla

Affected software:
Mozilla Firefox

The vulnerability allows a remote attacker to perform spoofing attack.

On pages containing an iframe, the data: protocol can be used to create a modal dialog through Javascript that will have an arbitrary domains as the dialog's location, spoofing of the origin of the modal dialog from the user view.

Note: This attack only affects installations with e10 multiprocess turned off. Installations with e10s turned on do not support the modal dialog functionality.

Update to version 56.0.

• https://www.mozilla.org/en-US/security/advisories/mfsa2017-21/