boot/grub2: ignore CVE-2023-4001

This vulnerability is irrelevant to Buildroot, as it affects only some
downstream changes from Redhat.

See:

  https://security-tracker.debian.org/tracker/CVE-2023-4001
  https://www.openwall.com/lists/oss-security/2024/01/15/3

Signed-off-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>

boot/grub2/grub2.mk

@@ -25,6 +25,9 @@ GRUB2_IGNORE_CVES += CVE-2019-14865
 GRUB2_IGNORE_CVES += CVE-2020-15705
 # vulnerability is specific to the SUSE distribution
 GRUB2_IGNORE_CVES += CVE-2021-46705
+# vulnerability is specific to the Redhat distribution, affects a
+# downstream change from Redhat related to password authentication
+GRUB2_IGNORE_CVES += CVE-2023-4001
 # vulnerability is specific to the Redhat distribution, affects the
 # grub2-set-bootflag tool, which doesn't exist upstream
 GRUB2_IGNORE_CVES += CVE-2024-1048