A specially crafted web-page can trigger a memory corruption vulnerability in Microsoft Internet Explorer 9. I did not investigate this vulnerability thoroughly, so I cannot speculate on the potential impact or exploitability.
Microsoft Internet Explorer 9
An attacker would need to get a target user to open a specially crafted web-page. JavaScript does not appear to be required for an attacker to triggering the vulnerable code path.
This bug was found back when I had very little knowledge and tools to do
analysis on use-after-free bugs, so I have no details to share. The EIP
provided me with some details of their analysis, which I'll paraphrase here:
It is a use-after-free vulnerability where the span object in the frame.FreeEntryOffset
value is stored at offset 0. This
value is then used as part of a pointer to a vftable in order to call a method.
This pointer now consist of the upper 16-bits of the old vftable and the lower
16-bits contain the FreeEntryOffset
value. Exploitation is near impossible
without a way to have more control over this pointer in the freed memory block.
ZDI also did a more thorough analysis and provide very similar details in
their advisory.
I have included a number of reports created using a predecessor of BugId
below.
This report was generated using a predecessor of BugId, a Python script created to detect, analyze and id application bugs. Don't waste time manually analyzing issues and writing reports but try BugId out yourself today! You'll get even better reports than this one with the current version. BugId report: Arbitrary AVR@MSHTML.id: Arbitrary AVR@MSHTML.dll!CTreeNode:: DelLookasidePtr(of6M) description: Security: Attempt to read from unallocated arbitrary memory (@0x18E30FA0) in MSHTML. dll!CTreeNode:: DelLookasidePtr note: Based on this information, this is expected to be a security issue! application: MSIE 9. 00. 8112. 16421 x64
This report was generated using a predecessor of BugId, a Python script created to detect, analyze and id application bugs. Don't waste time manually analyzing issues and writing reports but try BugId out yourself today! You'll get even better reports than this one with the current version.id: Arbitrary AVR@MSHTML.dll!CTreeNode:: VoidCachedNodeInfo(APRI) description: Security: Attempt to read from unallocated arbitrary memory (@0x12347FD0) in MSHTML. dll!CTreeNode:: VoidCachedNodeInfo note: Based on this information, this is expected to be a security issue! application: MSIE 9. 00. 8112. 16421 x86