There's a possible overflow in handle_image() when shim tries to load and execute crafted EFI executables; The handle_image() function takes into account the SizeOfRawData field from each section to be loaded. An attacker can leverage this to perform out-of-bound writes into memory. Arbitrary code execution is not discarded in such scenario.

References

• https://nvd.nist.gov/vuln/detail/CVE-2022-28737
• https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2022-28737
• https://www.openwall.com/lists/oss-security/2022/06/07/5