There is an issue with grub2 before version 2.06 while handling symlink on ext filesystems. A filesystem containing a symbolic link with an inode size of UINT32_MAX causes an arithmetic overflow leading to a zero-sized memory allocation with subsequent heap-based buffer overflow.
https://bugzilla.redhat.com/show_bug.cgi?id=CVE-2020-14311
https://usn.ubuntu.com/4432-1/
http://lists.opensuse.org/opensuse-security-announce/2020-08/msg00017.html
http://lists.opensuse.org/opensuse-security-announce/2020-08/msg00016.html
https://security.gentoo.org/glsa/202104-05
http://www.openwall.com/lists/oss-security/2021/09/17/2
Source: MITRE
Published: 2020-07-31
Updated: 2021-10-19
Type: CWE-190
Base Score: 3.6
Vector: AV:L/AC:L/Au:N/C:N/I:P/A:P
Impact Score: 4.9
Exploitability Score: 3.9
Severity: LOW
Base Score: 6
Vector: CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:N/I:H/A:H
Impact Score: 5.2
Exploitability Score: 0.8
Severity: MEDIUM