There's a use-after-free vulnerability in grub_cmd_chainloader() function; The chainloader command is used to boot up operating systems that doesn't support multiboot and do not have direct support from GRUB2. When executing chainloader more than once a use-after-free vulnerability is triggered. If an attacker can control the GRUB2's memory allocation pattern sensitive data may be exposed and arbitrary code execution can be achieved.

References

• https://nvd.nist.gov/vuln/detail/CVE-2022-28736
• https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2022-28736
• https://www.openwall.com/lists/oss-security/2022/06/07/5
• https://security.netapp.com/advisory/ntap-20230825-0002