Vulnerabilities > CVE-2020-15707 - Integer Overflow or Wraparound vulnerability in multiple products
Attack vector
LOCAL Attack complexity
MEDIUM Privileges required
NONE Confidentiality impact
PARTIAL Integrity impact
PARTIAL Availability impact
PARTIAL Summary
Integer overflows were discovered in the functions grub_cmd_initrd and grub_initrd_init in the efilinux component of GRUB2, as shipped in Debian, Red Hat, and Ubuntu (the functionality is not included in GRUB2 upstream), leading to a heap-based buffer overflow. These could be triggered by an extremely large number of arguments to the initrd command on 32-bit architectures, or a crafted filesystem with very large files on any architecture. An attacker could use this to execute arbitrary code and bypass UEFI Secure Boot restrictions. This issue affects GRUB2 version 2.04 and prior versions.
Vulnerable Configurations
| Part | Description | Count |
|---|---|---|
| Application | 7 | |
| Application | 2 | |
| Application | 1 | |
| OS | 2 | |
| OS | Microsoft
| 17 |
| OS | 4 | |
| OS | 1 | |
| OS | 2 | |
| OS | 3 |
Common Weakness Enumeration (CWE)
Common Attack Pattern Enumeration and Classification (CAPEC)
- Forced Integer Overflow This attack forces an integer variable to go out of range. The integer variable is often used as an offset such as size of memory allocation or similarly. The attacker would typically control the value of such variable and try to get it out of range. For instance the integer in question is incremented past the maximum possible value, it may wrap to become a very small, or negative number, therefore providing a very incorrect value which can lead to unexpected behavior. At worst the attacker can execute arbitrary code.
References
- https://www.suse.com/support/kb/doc/?id=000019673
- http://ubuntu.com/security/notices/USN-4432-1
- https://lists.gnu.org/archive/html/grub-devel/2020-07/msg00034.html
- https://wiki.ubuntu.com/SecurityTeam/KnowledgeBase/GRUB2SecureBootBypass
- https://www.debian.org/security/2020-GRUB-UEFI-SecureBoot
- https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/ADV200011
- https://access.redhat.com/security/vulnerabilities/grub2bootloader
- https://www.eclypsium.com/2020/07/29/theres-a-hole-in-the-boot/
- https://www.suse.com/c/suse-addresses-grub2-secure-boot-issue/
- https://www.openwall.com/lists/oss-security/2020/07/29/3
- https://www.debian.org/security/2020/dsa-4735
- http://www.openwall.com/lists/oss-security/2020/07/29/3
- https://security.netapp.com/advisory/ntap-20200731-0008/
- https://usn.ubuntu.com/4432-1/
- http://lists.opensuse.org/opensuse-security-announce/2020-08/msg00017.html
- http://lists.opensuse.org/opensuse-security-announce/2020-08/msg00016.html
- https://security.gentoo.org/glsa/202104-05