Immunity, Inc.
Name ie_mshtml_doublefree
CVE CVE-2021-26411
Exploit Pack CANVAS
Descriptionie_mshtml_doublefree
NotesCVE Name: CVE-2021-26411
VENDOR: Microsoft
NOTES: This exploit targets a double-free in ie9_removeAttributeNodeInternal.
The function first finds two indices for the node entry in the attribute
array. The use-after-free occurs because there is a user-controlled
callback between the calculating the indices and when they are used.
The backing store buffer can be changed during this callback and the code
doesn't verify that the index is still valid.

IMPORTANT: In the current version of the exploit, the exit_redirect
functionality is not working during the initial compromise.

VersionsAffected: Affects all Internet Explorer versions from 11.0 up to and including 11.630.19041.0
Repeatability: Infinite
References: - https://enki.co.kr/blog/2021/02/04/ie_0day.html
- https://iamelli0t.github.io/2021/03/12/CVE-2021-26411.html

CVE Url: https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2021-26411
Date public: 04/02/2021
CVSS: N/A

Learn more about the CANVAS Exploit Pack here: CANVAS