There's an issue with grub2 in all versions before 2.06 when handling squashfs filesystems containing a symbolic link with name length of UINT32 bytes in size. The name size leads to an arithmetic overflow leading to a zero-size allocation further causing a heap-based buffer overflow with attacker controlled data.
https://bugzilla.redhat.com/show_bug.cgi?id=1852022
https://security.netapp.com/advisory/ntap-20200731-0008/
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
Source: MITRE
Published: 2020-07-30
Updated: 2022-04-28
Type: CWE-787
Base Score: 4.6
Vector: AV:L/AC:L/Au:N/C:P/I:P/A:P
Impact Score: 6.4
Exploitability Score: 3.9
Severity: MEDIUM
Base Score: 6.7
Vector: CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H
Impact Score: 5.9
Exploitability Score: 0.8
Severity: MEDIUM