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.
The product performs a calculation that can produce an integer overflow or wraparound when the logic assumes that the resulting value will always be larger than the original value. This occurs when an integer value is incremented to a value that is too large to store in the associated representation. When this occurs, the value may become a very small or negative number.
| Link | Tags |
|---|---|
| https://bugzilla.redhat.com/show_bug.cgi?id=1852022 | issue tracking third party advisory |
| https://security.netapp.com/advisory/ntap-20200731-0008/ | third party advisory |
| https://usn.ubuntu.com/4432-1/ | third party advisory vendor advisory |
| http://lists.opensuse.org/opensuse-security-announce/2020-08/msg00017.html | mailing list third party advisory vendor advisory |
| http://lists.opensuse.org/opensuse-security-announce/2020-08/msg00016.html | mailing list third party advisory vendor advisory |
| https://security.gentoo.org/glsa/202104-05 | third party advisory vendor advisory |