USN-4992-1: GRUB 2 vulnerabilities

18 June 2021

Several security issues were fixed in GRUB 2.

Releases

Packages

Details

Máté Kukri discovered that the acpi command in GRUB 2 allowed privileged
users to load crafted ACPI tables when secure boot is enabled. An attacker
could use this to bypass UEFI Secure Boot restrictions. (CVE-2020-14372)

Chris Coulson discovered that the rmmod command in GRUB 2 contained a use-
after-free vulnerability. A local attacker could use this to execute
arbitrary code and bypass UEFI Secure Boot restrictions. (CVE-2020-25632)

Chris Coulson discovered that a buffer overflow existed in the command line
parser in GRUB 2. A local attacker could use this to execute arbitrary code
and bypass UEFI Secure Boot restrictions. (CVE-2020-27749)

It was discovered that the cutmem command in GRUB 2 did not honor secure
boot locking. A local attacker could use this to execute arbitrary code and
bypass UEFI Secure Boot restrictions. (CVE-2020-27779)

It was discovered that the option parser in GRUB 2 contained a heap
overflow vulnerability. A local attacker could use this to execute
arbitrary code and bypass UEFI Secure Boot restrictions. (CVE-2021-20225)

It was discovered that the menu rendering implementation in GRUB 2 did not
properly calculate the amount of memory needed in some situations, leading
to out-of-bounds writes. A local attacker could use this to execute
arbitrary code and bypass UEFI Secure Boot restrictions. (CVE-2021-20233)