JVN#33044255 GreaseKit and Creammonkey allows execution of userscript functions

Overview

GreaseKit and Creammonkey contains a vulnerability that can be exploited to execute functions for userscripts.

Products Affected

GreaseKit 1.2 through 1.3
Creammonkey 0.9 through 1.1

GreaseKit is the successor to Creammonkey.

Description

GreaseKit and Creammonkey are plugins that enable user scripting to Safari and other Apple Webkit applications, and they provide APIs callable only from userscripts.
GreaseKit and Creammonkey are vulnerable in allowing APIs called from a web page.

Impact

When a user views a specially crafted web page, a remote attacker can read or modify the configuration, or send HTTP requests to arbitrary websites via the above functions, within the web page on which a userscript is configured to run.

Solution

Update the Software
Apply the latest update provided by the developer.
If you use Creammonkey, we recommend that you upgrade to the latest version of its successor GreaseKit, available from the developer's website.

Vendor Status

Vendor	Status	Last Update	Vendor Notes
Kazuyoshi Kato	Vulnerable	2007/12/26

References

JPCERT/CC Addendum

Vulnerability Analysis by JPCERT/CC

Analyzed on 2007.12.26

Measures	Conditions	Severity
Access Required	Routed - can be attacked over the Internet using packets	High
Authentication	None - anonymous or no authentication (IP addresses do not count)	High
User Interaction Required	Simple - the user must be convinced to take a standard action that does not feel harmful to most users, such as click on a link or view a file	Medium
Exploit Complexity	Low - little to no expertise and/or luck required to exploit (cross-site scripting)	High

Description of each analysis measures

Credit

Other Information

JPCERT Alert
JPCERT Reports
CERT Advisory
CPNI Advisory
TRnotes
CVE
JVN iPedia	JVNDB-2007-000824