update: shim

[dongsupark]

Name: shim
CVEs: CVE-2023-40546, CVE-2023-40547, CVE-2023-40548, CVE-2023-40549, CVE-2023-40550, CVE-2023-40551
CVSSs: 5.5, 9.8, 7.4, 5.5, 5.5, 7.1
Action Needed: update to >= 15.8

Summary:

• CVE-2023-40546: A flaw was found in Shim when an error happened while creating a new ESL variable. If Shim fails to create the new variable, it tries to print an error message to the user; however, the number of parameters used by the logging function doesn't match the format string used by it, leading to a crash under certain circumstances.
• CVE-2023-40547: A remote code execution vulnerability was found in Shim. The Shim boot support trusts attacker-controlled values when parsing an HTTP response. This flaw allows an attacker to craft a specific malicious HTTP request, leading to a completely controlled out-of-bounds write primitive and complete system compromise.
• CVE-2023-40548: A buffer overflow was found in Shim in the 32-bit system. The overflow happens due to an addition operation involving a user-controlled value parsed from the PE binary being used by Shim. This value is further used for memory allocation operations, leading to a heap-based buffer overflow. This flaw causes memory corruption and can lead to a crash or data integrity issues during the boot phase.
• CVE-2023-40549: An out-of-bounds read flaw was found in Shim due to the lack of proper boundary verification during the load of a PE binary. This flaw allows an attacker to load a crafted PE binary, triggering the issue and crashing Shim, resulting in a denial of service.
• CVE-2023-40550: An out-of-bounds read flaw was found in Shim when it tried to validate the SBAT information. This issue may expose sensitive data during the system's boot phase.
• CVE-2023-40551: A flaw was found in the MZ binary format in Shim. An out-of-bounds read may occur, leading to a crash or possible exposure of sensitive data during the system's boot phase.

refmap.gentoo: https://bugs.gentoo.org/922931

[sayanchowdhury]

Updated to 15.8 in flatcar/scripts#1589. Closing the issue.