32%
18%
23%
A flaw was found in the Linux Kernel. The tls_is_tx_ready() incorrectly checks for list emptiness, potentially accessing a type confused entry to the list_head, leaking the last byte of the confused field that overlaps with rec->tx_ready.
CVSS 3.1 Base Score 3.3. CVSS Attack Vector: local. CVSS Attack Complexity: low. CVSS Vector: (CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N).
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.
ExploitPedia is constantly evolving. Sign up to receive a notification when we release additional functionality.
If you'd like to report a bug or have any suggestions for improvements then please do get in touch with us using this form. We will get back to you as soon as we can.