CVE-2020-0224 - Access of Resource Using Incompatible Type ('Type Confusion')

Severity

98%

Complexity

39%

Confidentiality

98%

In FastKeyAccumulator::GetKeysSlow of keys.cc, there is a possible out of bounds write due to type confusion. This could lead to remote code execution when processing a proxy configuration with no additional execution privileges needed. User interaction is not needed for exploitation.Product: AndroidVersions: Android-8.0 Android-8.1 Android-9 Android-10Android ID: A-147664838

CVSS 3.1 Base Score 9.8. CVSS Attack Vector: network. CVSS Attack Complexity: low. CVSS Vector: (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H).

CVSS 2.0 Base Score 9.9. CVSS Attack Vector: network. CVSS Attack Complexity: low. CVSS Vector: (AV:N/AC:L/Au:N/C:C/I:C/A:C).

Demo Examples

Access of Resource Using Incompatible Type ('Type Confusion')

CWE-843

Access of Resource Using Incompatible Type ('Type Confusion')

CWE-843

Access of Resource Using Incompatible Type ('Type Confusion')

CWE-843

The following Perl code is intended to look up the privileges for user ID's between 0 and 3, by performing an access of the $UserPrivilegeArray reference. It is expected that only userID 3 is an admin (since this is listed in the third element of the array).


               
print "\$UserPrivilegeArray = $UserPrivilegeArray\n";
print "Regular user!\n";
print "Admin!\n";

In this case, the programmer intended to use "$UserPrivilegeArray->{$userID}" to access the proper position in the array. But because the subscript was omitted, the "user" string was compared to the scalar representation of the $UserPrivilegeArray reference, which might be of the form "ARRAY(0x229e8)" or similar.

Since the logic also "fails open" (CWE-636), the result of this bug is that all users are assigned administrator privileges.

While this is a forced example, it demonstrates how type confusion can have security consequences, even in memory-safe languages.

Overview

Type

Google Android

First reported 4 years ago

2020-07-17 21:15:00

Last updated 4 years ago

2020-07-22 14:53:00

Affected Software

Google Android 8.0

8.0

Google Android 8.1

8.1

Google Android 9.0

9.0

Google Android 10.0

10.0

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