Gentoo update for GRUB

1) Out-of-bounds Write

EUVDB-ID: #VU32922

Risk: Low

CVSSv3.1: 6.1 [CVSS:3.1/AV:P/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H/E:P/RL:O/RC:C]

CVE-ID: CVE-2020-10713

CWE-ID: CWE-787 - Out-of-bounds write

Exploit availability: Yes

Description

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.

Mitigation

Update the affected packages.
sys-devel/grub to version:

Vulnerable software versions

Gentoo Linux: All versions

External links

http://security.gentoo.org/
http://security.gentoo.org/glsa/202104-05

Q & A

Can this vulnerability be exploited remotely?

No. The attacker should have physical access to the system in order to successfully exploit this vulnerability.

Is there known malware, which exploits this vulnerability?

No. We are not aware of malware exploiting this vulnerability. However, proof of concept for this vulnerability is available.

2) Heap-based buffer overflow

EUVDB-ID: #VU32923

Risk: Low

CVSSv3.1: 5.9 [CVSS:3.1/AV:P/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C]

CVE-ID: CVE-2020-14308

CWE-ID: CWE-122 - Heap-based Buffer Overflow

Exploit availability: No

Description

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.

Mitigation

Update the affected packages.
sys-devel/grub to version:

Vulnerable software versions

Gentoo Linux: All versions

External links

http://security.gentoo.org/
http://security.gentoo.org/glsa/202104-05

Q & A

Can this vulnerability be exploited remotely?

No. The attacker should have physical access to the system in order to successfully exploit this vulnerability.

Is there known malware, which exploits this vulnerability?

No. We are not aware of malware exploiting this vulnerability.

3) Integer overflow

EUVDB-ID: #VU32934

Risk: Low

CVSSv3.1: 5.7 [CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:N/I:N/A:H/E:U/RL:O/RC:C]

CVE-ID: CVE-2020-14309

CWE-ID: CWE-190 - Integer overflow

Exploit availability: No

Description

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.

Mitigation

Update the affected packages.
sys-devel/grub to version:

Vulnerable software versions

Gentoo Linux: All versions

External links

http://security.gentoo.org/
http://security.gentoo.org/glsa/202104-05

Q & A

Can this vulnerability be exploited remotely?

No. This vulnerability can be exploited locally. The attacker should have authentication credentials and successfully authenticate on the system.

Is there known malware, which exploits this vulnerability?

No. We are not aware of malware exploiting this vulnerability.

4) Integer overflow

EUVDB-ID: #VU32935

Risk: Low

CVSSv3.1: 5.7 [CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:N/I:N/A:H/E:U/RL:O/RC:C]

CVE-ID: CVE-2020-14310

CWE-ID: CWE-190 - Integer overflow

Exploit availability: No

Description

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.

Mitigation

Update the affected packages.
sys-devel/grub to version:

Vulnerable software versions

Gentoo Linux: All versions

External links

http://security.gentoo.org/
http://security.gentoo.org/glsa/202104-05

Q & A

Can this vulnerability be exploited remotely?

No. This vulnerability can be exploited locally. The attacker should have authentication credentials and successfully authenticate on the system.

Is there known malware, which exploits this vulnerability?

No. We are not aware of malware exploiting this vulnerability.

5) Integer overflow

EUVDB-ID: #VU32936

Risk: Low

CVSSv3.1: 5.7 [CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:N/I:N/A:H/E:U/RL:O/RC:C]

CVE-ID: CVE-2020-14311

CWE-ID: CWE-190 - Integer overflow

Exploit availability: No

Description

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.

Mitigation

Update the affected packages.
sys-devel/grub to version:

Vulnerable software versions

Gentoo Linux: All versions

External links

http://security.gentoo.org/
http://security.gentoo.org/glsa/202104-05

Q & A

Can this vulnerability be exploited remotely?

No. This vulnerability can be exploited locally. The attacker should have authentication credentials and successfully authenticate on the system.

Is there known malware, which exploits this vulnerability?

No. We are not aware of malware exploiting this vulnerability.

6) Security restrictions bypass

EUVDB-ID: #VU51187

Risk: Low

CVSSv3.1: 5.6 [CVSS:3.1/AV:L/AC:H/PR:H/UI:N/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C]

CVE-ID: CVE-2020-14372

CWE-ID: CWE-264 - Permissions, Privileges, and Access Controls

Exploit availability: Yes

Description

The vulnerability allows a local privileged user to bypass implemented security restrictions.

The vulnerability exists due to GRUB enables usage of the acpi command even when Secure Boot is enabled by firmware. A local user with root privileges can put a small SSDT into /boot/efi folder and modify the grub.cfg file to load that SSDT during kernel boot. The SSDT then gets run by the kernel and it overwrites the kernel lock down configuration enabling the attacker to load unsigned kernel modules and kexec unsigned code.

Mitigation

Update the affected packages.
sys-devel/grub to version:

Vulnerable software versions

Gentoo Linux: All versions

External links

http://security.gentoo.org/
http://security.gentoo.org/glsa/202104-05

Q & A

Can this vulnerability be exploited remotely?

No. This vulnerability can be exploited locally. The attacker should have authentication credentials and successfully authenticate on the system.

Is there known malware, which exploits this vulnerability?

No. We are not aware of malware exploiting this vulnerability.

7) Improper Verification of Cryptographic Signature

EUVDB-ID: #VU32927

Risk: Low

CVSSv3.1: 5.9 [CVSS:3.1/AV:P/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C]

CVE-ID: CVE-2020-15705

CWE-ID: CWE-347 - Improper Verification of Cryptographic Signature

Exploit availability: No

Description

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.

Mitigation

Update the affected packages.
sys-devel/grub to version:

Vulnerable software versions

Gentoo Linux: All versions

External links

http://security.gentoo.org/
http://security.gentoo.org/glsa/202104-05

Q & A

Can this vulnerability be exploited remotely?

No. The attacker should have physical access to the system in order to successfully exploit this vulnerability.

Is there known malware, which exploits this vulnerability?

No. We are not aware of malware exploiting this vulnerability.

8) Race condition

EUVDB-ID: #VU32926

Risk: Low

CVSSv3.1: 5.9 [CVSS:3.1/AV:P/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C]

CVE-ID: CVE-2020-15706

CWE-ID: CWE-362 - Concurrent Execution using Shared Resource with Improper Synchronization ('Race Condition')

Exploit availability: No

Description

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.

Mitigation

Update the affected packages.
sys-devel/grub to version:

Vulnerable software versions

Gentoo Linux: All versions

External links

http://security.gentoo.org/
http://security.gentoo.org/glsa/202104-05

Q & A

Can this vulnerability be exploited remotely?

No. The attacker should have physical access to the system in order to successfully exploit this vulnerability.

Is there known malware, which exploits this vulnerability?

No. We are not aware of malware exploiting this vulnerability.

9) Integer overflow

EUVDB-ID: #VU32925

Risk: Low

CVSSv3.1: 5.9 [CVSS:3.1/AV:P/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C]

CVE-ID: CVE-2020-15707

CWE-ID: CWE-190 - Integer overflow

Exploit availability: No

Description

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.

Mitigation

Update the affected packages.
sys-devel/grub to version:

Vulnerable software versions

Gentoo Linux: All versions

External links

http://security.gentoo.org/
http://security.gentoo.org/glsa/202104-05

Q & A

Can this vulnerability be exploited remotely?

No. The attacker should have physical access to the system in order to successfully exploit this vulnerability.

Is there known malware, which exploits this vulnerability?

No. We are not aware of malware exploiting this vulnerability.

10) Use-after-free

EUVDB-ID: #VU51188

Risk: Low

CVSSv3.1: 5.8 [CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C]

CVE-ID: CVE-2020-25632

CWE-ID: CWE-416 - Use After Free

Exploit availability: Yes

Description

The vulnerability allows a local user to bypass implemented security restrictions.

The vulnerability exists due to a use-after-free error when handling module unloads. A local privileged user can unload a kernel module, trigger a use-after-free error and bypass Secure Boot protection mechanism.

Mitigation

Update the affected packages.
sys-devel/grub to version:

Vulnerable software versions

Gentoo Linux: All versions

External links

http://security.gentoo.org/
http://security.gentoo.org/glsa/202104-05

Q & A

Can this vulnerability be exploited remotely?

No. This vulnerability can be exploited locally. The attacker should have authentication credentials and successfully authenticate on the system.

Is there known malware, which exploits this vulnerability?

No. We are not aware of malware exploiting this vulnerability.

11) Out-of-bounds write

EUVDB-ID: #VU51189

Risk: Low

CVSSv3.1: 5.9 [CVSS:3.1/AV:P/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C]

CVE-ID: CVE-2020-25647

CWE-ID: CWE-787 - Out-of-bounds write

Exploit availability: No

Description

The vulnerability allows a local user to escalate privileges on the system.

The vulnerability exists due to a boundary error when processing untrusted input from USB device in grub_usb_device_initialize(). An attacker with physical access to the system can trigger an out-of-bounds write error with a malicious USB drive, bypass Secure Boot protection and execute arbitrary code on the system with elevated privileges.

Mitigation

Update the affected packages.
sys-devel/grub to version:

Vulnerable software versions

Gentoo Linux: All versions

External links

http://security.gentoo.org/
http://security.gentoo.org/glsa/202104-05

Q & A

Can this vulnerability be exploited remotely?

No. The attacker should have physical access to the system in order to successfully exploit this vulnerability.

Is there known malware, which exploits this vulnerability?

No. We are not aware of malware exploiting this vulnerability.

12) Stack-based buffer overflow

EUVDB-ID: #VU51193

Risk: Low

CVSSv3.1: 5.8 [CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C]

CVE-ID: CVE-2020-27749

CWE-ID: CWE-121 - Stack-based buffer overflow

Exploit availability: No

Description

The vulnerability allows a local user to escalate privileges on the system.

The vulnerability exists due to a boundary error within the grub_parser_split_cmdline() function while expanding variable names present in the supplied command line in to their corresponding variable contents. A local privileged user can run a specially crafted program to trigger the stack-based buffer overflow and bypass Secure Boot protection.

Mitigation

Update the affected packages.
sys-devel/grub to version:

Vulnerable software versions

Gentoo Linux: All versions

External links

http://security.gentoo.org/
http://security.gentoo.org/glsa/202104-05

Q & A

Can this vulnerability be exploited remotely?

No. This vulnerability can be exploited locally. The attacker should have authentication credentials and successfully authenticate on the system.

Is there known malware, which exploits this vulnerability?

No. We are not aware of malware exploiting this vulnerability.

13) Improper Authorization

EUVDB-ID: #VU51194

Risk: Low

CVSSv3.1: 6.1 [CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C]

CVE-ID: CVE-2020-27779

CWE-ID: CWE-285 - Improper Authorization

Exploit availability: No

Description

The vulnerability allows a local user to bypass authorization checks.

The vulnerability exists within the cutmem command, which does not honor the Secure Boot locking. A local privileged user can remove address ranges from memory creating an opportunity to circumvent Secure Boot protections after proper triage about grub's memory layout.

Mitigation

Update the affected packages.
sys-devel/grub to version:

Vulnerable software versions

Gentoo Linux: All versions

External links

http://security.gentoo.org/
http://security.gentoo.org/glsa/202104-05

Q & A

Can this vulnerability be exploited remotely?

No. This vulnerability can be exploited locally. The attacker should have authentication credentials and successfully authenticate on the system.

Is there known malware, which exploits this vulnerability?

No. We are not aware of malware exploiting this vulnerability.

14) Out-of-bounds write

EUVDB-ID: #VU51197

Risk: Low

CVSSv3.1: 5.6 [CVSS:3.1/AV:L/AC:H/PR:H/UI:N/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C]

CVE-ID: CVE-2021-20225

CWE-ID: CWE-787 - Out-of-bounds write

Exploit availability: No

Description

The vulnerability allows a local user to escalate privileges on the system.

The vulnerability exists due to a boundary error within the option parser. A local privileged user can write past the end of a heap-allocated buffer by calling certain commands with a large number of specific short forms of options and execute arbitrary code with elevated privileges.

Mitigation

Update the affected packages.
sys-devel/grub to version:

Vulnerable software versions

Gentoo Linux: All versions

External links

http://security.gentoo.org/
http://security.gentoo.org/glsa/202104-05

Q & A

Can this vulnerability be exploited remotely?

No. This vulnerability can be exploited locally. The attacker should have authentication credentials and successfully authenticate on the system.

Is there known malware, which exploits this vulnerability?

No. We are not aware of malware exploiting this vulnerability.

15) Out-of-bounds write

EUVDB-ID: #VU51198

Risk: Low

CVSSv3.1: 5.6 [CVSS:3.1/AV:L/AC:H/PR:H/UI:N/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C]

CVE-ID: CVE-2021-20233

CWE-ID: CWE-787 - Out-of-bounds write

Exploit availability: Yes

Description

The vulnerability allows a local user to escalate privileges on the system.

The vulnerability exists due to a boundary error within the setparam_prefix() function in menu rendering code. A local privileged user can run a specially crafted program to trigger out-of-bounds write and escalate privileges on the system.

Mitigation

Update the affected packages.
sys-devel/grub to version:

Vulnerable software versions

Gentoo Linux: All versions

External links

http://security.gentoo.org/
http://security.gentoo.org/glsa/202104-05

Q & A

Can this vulnerability be exploited remotely?

No. This vulnerability can be exploited locally. The attacker should have authentication credentials and successfully authenticate on the system.

Is there known malware, which exploits this vulnerability?

No. We are not aware of malware exploiting this vulnerability.

Risk	Low
Patch available	YES
Number of vulnerabilities	15
CVE-ID	CVE-2020-10713 CVE-2020-14308 CVE-2020-14309 CVE-2020-14310 CVE-2020-14311 CVE-2020-14372 CVE-2020-15705 CVE-2020-15706 CVE-2020-15707 CVE-2020-25632 CVE-2020-25647 CVE-2020-27749 CVE-2020-27779 CVE-2021-20225 CVE-2021-20233
CWE-ID	CWE-787 CWE-122 CWE-190 CWE-264 CWE-347 CWE-362 CWE-416 CWE-121 CWE-285
Exploitation vector	Local
Public exploit	Public exploit code for vulnerability #1 is available. Public exploit code for vulnerability #6 is available. Public exploit code for vulnerability #10 is available. Public exploit code for vulnerability #15 is available.
Vulnerable software Subscribe	Gentoo Linux Operating systems & Components / Operating system
Vendor	Gentoo