CVE-2017-11305

Vulnerability

A regression in Adobe Flash Player version 27.0.0.187 and earlier causes the unintended reset of the global settings preference file when a user clears browser data [1]. This allows an attacker to craft a specially crafted SWF file that, when loaded by the victim, can modify these settings after the reset occurs.

Exploitation

An attacker must deliver a malicious SWF file to the victim, who must be using an affected version of Flash Player (up to 27.0.0.187) with Flash enabled [1]. The victim then needs to load a page containing the SWF content. Subsequently, when the user clears browser data (e.g., cookies, cache), the global settings preference file is reset, allowing the attacker's content to influence settings [1].

Impact

Successful exploitation allows an attacker to modify the global settings preference file [1], potentially disabling security features, altering storage settings, or facilitating further attacks. This could lead to disclosure of sensitive information or compromise of the Flash environment [1].

Mitigation

Adobe released Flash Player version 28.0.0.137 to address this vulnerability [1]. Red Hat provided patched packages via RHSA-2018:0081 for Red Hat Enterprise Linux 6 [1]. Users should update to the latest version immediately. If updating is not possible, consider disabling Flash Player or restricting untrusted SWF files.