SB2020073035 - Red Hat 8.1 update for grub2
Published: July 30, 2020
Breakdown by Severity
- Low
- Medium
- High
- Critical
Description
This security bulletin contains information about 8 secuirty vulnerabilities.
1) Out-of-bounds Write (CVE-ID: CVE-2020-10713)
The vulnerability allows a local attacker to compromise vulnerable system.
The vulnerability exists due to a "BootHole" issue. An attacker with physical access can install persistent and stealthy bootkits or malicious bootloaders, trigger out-of-bounds write and execute arbitrary code on the target system.
2) Heap-based buffer overflow (CVE-ID: CVE-2020-14308)
The vulnerability allows a local attacker to execute arbitrary code on the target system.
The vulnerability exists due to a boundary error. An attacker with physical access can trigger heap-based buffer overflow and execute arbitrary code on the target system during the boot process.
Successful exploitation of this vulnerability may result in complete compromise of vulnerable system.
3) Integer overflow (CVE-ID: CVE-2020-14309)
The vulnerability allows a local user to perform a denial of service (DoS) attack.
The vulnerability exists due to integer overflow when handling symlinks on ext filesustem in grub_squash_read_symlink() function. A local user can create a specially crafted symlink, trigger an integer overflow and crash the system.
4) Integer overflow (CVE-ID: CVE-2020-14310)
The vulnerability allows a local user to perform a denial of service (DoS) attack.
The vulnerability exists due to integer overflow within the read_section_as_string() function when processing font names. A local user can create a specially crafted font name, trigger integer overflow and crash the affected system.
5) Integer overflow (CVE-ID: CVE-2020-14311)
The vulnerability allows a local user to perform a denial of service (DoS) attack.
The vulnerability exists due to integer overflow within the grub_ext2_read_link() function when processing symlinks. A local user can create a specially crafted symlink, trigger integer overflow and crash the system.
6) Improper Verification of Cryptographic Signature (CVE-ID: CVE-2020-15705)
The vulnerability allows a local attacker to compromise the target system.
The vulnerability exists due to the affected software fails to validate kernel signature when booted directly without shim. An attacker with physical access can bypass secure boot.
7) Race condition (CVE-ID: CVE-2020-15706)
The vulnerability allows a local attacker to execute arbitrary code and bypass secure boot restriction.
The vulnerability exists due to a race condition in the "grub_script_function_create()" function. An attacker with physical access can exploit the race and execute arbitrary code on the target system.
8) Integer overflow (CVE-ID: CVE-2020-15707)
The vulnerability allows a local attacker to execute arbitrary code on the target system.
The vulnerability exists due to integer overflow in the "grub_cmd_initrd" and "grub_initrd_init" functions in the "efilinux" component. An attacker with physical access can pass specially crafted data to the application, trigger integer overflow and execute arbitrary code on the target system.
Successful exploitation of this vulnerability may result in complete compromise of vulnerable system.
Remediation
Install update from vendor's website.