Headline
CVE-2021-20233: Heap out-of-bounds write due to miscalculation of space required for quoting
A flaw was found in grub2 in versions prior to 2.06. Setparam_prefix() in the menu rendering code performs a length calculation on the assumption that expressing a quoted single quote will require 3 characters, while it actually requires 4 characters which allows an attacker to corrupt memory by one byte for each quote in the input. The highest threat from this vulnerability is to data confidentiality and integrity as well as system availability.
Description Marco Benatto 2021-02-08 14:18:19 UTC
There’s a flaw on grub2 menu rendering code setparam_prefix() in the menu rendering code performs a length calculation on the assumption that expressing a quoted single quote will require 3 characters, while it actually requires 4 characters. This allow an attacker to corrupt memory by one byte for each quote in the input.
Comment 2 Marian Rehak 2021-02-23 11:10:34 UTC
*** Bug 1927436 has been marked as a duplicate of this bug. ***
Comment 6 Marco Benatto 2021-03-02 18:40:48 UTC
Created grub2 tracking bugs for this issue:
Affects: fedora-all [bug 1934252]
Comment 12 errata-xmlrpc 2021-03-02 20:09:44 UTC
This issue has been addressed in the following products:
Red Hat Enterprise Linux 7.4 Advanced Update Support Red Hat Enterprise Linux 7.4 Update Services for SAP Solutions Red Hat Enterprise Linux 7.4 Telco Extended Update Support
Via RHSA-2021:0702 https://access.redhat.com/errata/RHSA-2021:0702