There is an issue on grub2 before version 2.06 at function read_section_as_string(). It expects a font name to be at max UINT32_MAX – 1 length in bytes but it doesn’t verify it before proceed with buffer allocation to read the value from the font value. An attacker may leverage that by crafting a malicious font file which has a name with UINT32_MAX, leading to read_section_as_string() to an arithmetic overflow, zero-sized allocation and further heap-based buffer overflow.
Source: https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2020-14310
Reference (s):
- https://bugzilla.redhat.com/show_bug.cgi?id=CVE-2020-14310
- URL: https://bugzilla.redhat.com/show_bug.cgi?id=CVE-2020-14310
- GENTOO:GLSA-202104-05
- URL: https://security.gentoo.org/glsa/202104-05
- SUSE:openSUSE-SU-2020:1168