USN-4992-1

Dashboard / Vulnerabilities / USN-4992-1

USN-4992-1

Summary: grub2-signed, grub2-unsigned vulnerabilities

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)

References: https://ubuntu.com/security/notices/USN-4992-1, https://ubuntu.com/security/CVE-2020-14372, https://ubuntu.com/security/CVE-2020-25632, https://ubuntu.com/security/CVE-2020-27749, https://ubuntu.com/security/CVE-2020-27779, https://ubuntu.com/security/CVE-2021-20225, https://ubuntu.com/security/CVE-2021-20233