CVE-2022-28736: gnu project gnu grub Use After Free

Vulnerability summary

CVE-2022-28736 is a high (CVSS 7.8) Use After Free vulnerability in gnu project gnu grub. EPSS estimates a 0.29% chance of exploitation in the next 30 days, higher than 19.8% of scored vulnerabilities.

Timeline

1. 20-07-2023
   PublishedVulnerability first disclosed.
2. 13-02-2025
   Last modifiedVulnerability information updated.

Description

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.

• CWE-416Use After FreeThe product reuses or references memory after it has been freed. At some point afterward, the memory may be allocated again and saved in another pointer, while the original pointer references a location somewhere within the new allocation. Any operations using the original pointer are no longer valid because the memory "belongs" to the code that operates on the new pointer.