Exploitalert - Database of Exploits

Google Chrome 19 metro_driver.dll mishandling

CVE	Category	Price	Severity
CVE-2012-2764	CWE-119	Not specified	High

Author	Risk	Exploitation Type	Date
Unknown	High	Local	2012-07-23

CVSS	EPSS	EPSSP
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:H	0.02192	0.50148

CVSS vector description

Metric	Value	Metric Description	Value Description
Attack vector	Network	AV	The vulnerable system is bound to the network stack and the set of possible attackers extends beyond the other options listed below, up to and including the entire Internet. Such a vulnerability is often termed “remotely exploitable” and can be thought of as an attack being exploitable at the protocol level one or more network hops away (e.g., across one or more routers). An example of a network attack is an attacker causing a denial of service by sending a specially crafted TCP packet across a wide area network (e.g., CVE-2004-0230).
Attack Complexity	Low	AC	The attacker must take no measurable action to exploit the vulnerability. The attack requires no target-specific circumvention to exploit the vulnerability. An attacker can expect repeatable success against the vulnerable system.
Privileges Required	None	PR	The attacker is unauthenticated prior to attack, and therefore does not require any access to settings or files of the vulnerable system to carry out an attack.
Scope		S	An exploited vulnerability can affect resources beyond the security scope managed by the security authority that is managing the vulnerable component. This is often referred to as a 'privilege escalation,' where the attacker can use the exploited vulnerability to gain control of resources that were not intended or authorized.
Confidentiality	High	C	There is total information disclosure, resulting in all data on the system being revealed to the attacker, or there is a possibility of the attacker gaining control over confidential data.
Integrity	High	I	There is a total compromise of system integrity. There is a complete loss of system protection, resulting in the attacker being able to modify any file on the target system.
Availability	High	A	There is a total shutdown of the affected resource. The attacker can deny access to the system or data, potentially causing significant loss to the organization.

http://cxsecurity.com/ascii/WLB-2012070118

Security Advisory - Google Chrome 19 metro_driver.dll mishandling ====== Summary : Google Chrome 19 is prone to unqualified DLL loading Date : 28 June 2012 Affected versions : Google Chrome v19.0.1084.21 up-to v20.0.1132.23 ID : chromium#130276 CVE reference : CVE-2012-2764 Details ================ Google Chrome developers, while trying to be adaptive and current, added some windows 8 helper functions to aid the development of Metro style behaviour, but does not include the library file itself, thus resulting in an unqualified dynamic-link library call to 'metro_driver.dll'. A user with local disk access can carefuly construct a DLL that suits the pattern that is being traversed by the client and implement it somewhere along the search path and the client will load it seamlessly. Impact ================ After the DLL has been implemented, an unsuspected user that will run Chrome will cause it to load, resulting in arbitrary code execution under user's privilege level. This vector of attack is mainly used in a local privilege escalation scenarios, user credential harvesting and can be used by malware to disguise itself, amongst other uses. Proof of Concept ================ #include <windows.h> int hijack_poc () { WinExec ( "calc.exe" , SW_NORMAL ); return 0 ; } BOOL WINAPI DllMain (HINSTANCE hinstDLL , DWORD dwReason , LPVOID lpvReserved ) { hijack_poc () ; return 0 ; } Solution ================ Google Chrome 20.0.1132.43 resolves the issue. Credits ================ The issue was responsibly reported by Moshe Zioni from Comsec Global Consulting. Timeline ================= 26 June 2012 Google officialy announce Google Chrome 20 stable, fix included 1 June 2012 Code reverted - Revision 139975 takes place 30 May 2012 First response from a Google code maintainer 30 May 2012 Bug reported by Moshe Zioni from Comsec Global Consulting References ================= Google Chrome http://www.google.com/chrome Revision details http://src.chromium.org/viewvc/chrome?view=rev&revision=139975 Comsec Global Consulting http://www.comsecglobal.com/

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