Advisory Details

August 11th, 2015

Microsoft Internet Explorer Filesystem Elevation of Privilege Vulnerability

ZDI-15-378
ZDI-CAN-2727

CVE ID CVE-2015-2430
CVSS SCORE 6.9, AV:L/AC:M/Au:N/C:C/I:C/A:C
AFFECTED VENDORS Microsoft
AFFECTED PRODUCTS Internet Explorer
VULNERABILITY DETAILS


This vulnerability allows attackers to escalate privileges on vulnerable installations of Microsoft Internet Explorer. User interaction is required to exploit this vulnerability in that the target must visit a malicious page or open a malicious file.

The specific flaw exists within the handling of junction points in the Favorites folder linked to other folders. An attacker running code in the context of a low-rights Internet Explorer process can set up a junction point in the Favorites folder and then the IE broker process will change access control rights in the targeted folders (which are normally unmodifiable by the low-rights process). An attacker can leverage this vulnerability to execute code under the context of a medium integrity process.

ADDITIONAL DETAILS Microsoft has issued an update to correct this vulnerability. More details can be found at:
https://technet.microsoft.com/library/security/MS15-090
DISCLOSURE TIMELINE
  • 2015-02-09 - Vulnerability reported to vendor
  • 2015-08-11 - Coordinated public release of advisory
CREDIT Ashutosh Mehra (https://twitter.com/ashutoshmehra)
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