CVE-2020-15706

CVE-2020-15706 is a medium-severity vulnerability in Gnu Grub2 with a CVSS 3.x base score of 6.4. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-362.

Key facts

• Severity: Medium (CVSS 3.x base score 6.4)
• CVSS v2: 4.4
• EPSS exploit prediction: 1% (58th percentile)
• Actively exploited: Not listed in CISA KEV
• Weakness: CWE-362
• Affected product: Gnu Grub2
• Published: 2020-07-29
• Last modified: 2026-06-17

Description

GRUB2 contains a race condition in grub_script_function_create() leading to a use-after-free vulnerability which can be triggered by redefining a function whilst the same function is already executing, leading to arbitrary code execution and secure boot restriction bypass. This issue affects GRUB2 version 2.04 and prior versions.

Frequently asked questions

What is CVE-2020-15706?

GRUB2 contains a race condition in grub_script_function_create() leading to a use-after-free vulnerability which can be triggered by redefining a function whilst the same function is already executing, leading to arbitrary code execution and secure boot restriction bypass. This issue affects GRUB2 version 2.04 and prior versions.

How severe is CVE-2020-15706?

CVE-2020-15706 has a CVSS 3.x base score of 6.4, rated medium severity. It is exploitable over local access with high attack complexity, requires high privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.

Is CVE-2020-15706 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (58th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2020-15706?

CVE-2020-15706 primarily affects Gnu Grub2. In total, 33 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2020-15706?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.

When was CVE-2020-15706 published?

CVE-2020-15706 was published on 2020-07-29 and last updated on 2026-06-17.

References

• http://lists.opensuse.org/opensuse-security-announce/2020-08/msg00016.html
• http://lists.opensuse.org/opensuse-security-announce/2020-08/msg00017.html
• http://ubuntu.com/security/notices/USN-4432-1
• http://www.openwall.com/lists/oss-security/2020/07/29/3
• https://access.redhat.com/security/vulnerabilities/grub2bootloader
• https://lists.gnu.org/archive/html/grub-devel/2020-07/msg00034.html
• https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/ADV200011
• https://security.gentoo.org/glsa/202104-05
• https://security.netapp.com/advisory/ntap-20200731-0008/
• https://usn.ubuntu.com/4432-1/
• https://wiki.ubuntu.com/SecurityTeam/KnowledgeBase/GRUB2SecureBootBypass
• https://www.debian.org/security/2020-GRUB-UEFI-SecureBoot
• https://www.debian.org/security/2020/dsa-4735
• https://www.eclypsium.com/2020/07/29/theres-a-hole-in-the-boot/
• https://www.openwall.com/lists/oss-security/2020/07/29/3
• https://www.suse.com/c/suse-addresses-grub2-secure-boot-issue/
• https://www.suse.com/support/kb/doc/?id=000019673

Affected products (33)

• cpe:2.3:a:gnu:grub2:*:*:*:*:*:*:*:*
• cpe:2.3:a:redhat:enterprise_linux_atomic_host:-:*:*:*:*:*:*:*
• cpe:2.3:a:redhat:openshift_container_platform:4.0:*:*:*:*:*:*:*
• cpe:2.3:o:canonical:ubuntu_linux:14.04:*:*:*:esm:*:*:*
• cpe:2.3:o:canonical:ubuntu_linux:16.04:*:*:*:lts:*:*:*
• cpe:2.3:o:canonical:ubuntu_linux:18.04:*:*:*:lts:*:*:*
• cpe:2.3:o:canonical:ubuntu_linux:20.04:*:*:*:lts:*:*:*
• cpe:2.3:o:debian:debian_linux:10.0:*:*:*:*:*:*:*
• cpe:2.3:o:redhat:enterprise_linux:7.0:*:*:*:*:*:*:*
• cpe:2.3:o:redhat:enterprise_linux:8.0:*:*:*:*:*:*:*
• cpe:2.3:o:suse:suse_linux_enterprise_server:11:*:*:*:*:*:*:*
• cpe:2.3:o:suse:suse_linux_enterprise_server:12:*:*:*:*:*:*:*
• cpe:2.3:o:suse:suse_linux_enterprise_server:15:*:*:*:*:*:*:*
• cpe:2.3:o:microsoft:windows_10:-:*:*:*:*:*:*:*
• cpe:2.3:o:microsoft:windows_10:1607:*:*:*:*:*:*:*
• cpe:2.3:o:microsoft:windows_10:1709:*:*:*:*:*:*:*
• cpe:2.3:o:microsoft:windows_10:1803:*:*:*:*:*:*:*
• cpe:2.3:o:microsoft:windows_10:1809:*:*:*:*:*:*:*
• cpe:2.3:o:microsoft:windows_10:1903:*:*:*:*:*:*:*
• cpe:2.3:o:microsoft:windows_10:1909:*:*:*:*:*:*:*
• cpe:2.3:o:microsoft:windows_10:2004:*:*:*:*:*:*:*
• cpe:2.3:o:microsoft:windows_8.1:-:*:*:*:*:*:*:*
• cpe:2.3:o:microsoft:windows_rt_8.1:-:*:*:*:*:*:*:*
• cpe:2.3:o:microsoft:windows_server_2012:-:*:*:*:*:*:*:*
• cpe:2.3:o:microsoft:windows_server_2012:r2:*:*:*:*:*:*:*
• cpe:2.3:o:microsoft:windows_server_2016:-:*:*:*:*:*:*:*
• cpe:2.3:o:microsoft:windows_server_2016:1903:*:*:*:*:*:*:*
• cpe:2.3:o:microsoft:windows_server_2016:1909:*:*:*:*:*:*:*
• cpe:2.3:o:microsoft:windows_server_2016:2004:*:*:*:*:*:*:*
• cpe:2.3:o:microsoft:windows_server_2019:-:*:*:*:*:*:*:*
• cpe:2.3:o:opensuse:leap:15.1:*:*:*:*:*:*:*
• cpe:2.3:o:opensuse:leap:15.2:*:*:*:*:*:*:*
• cpe:2.3:o:canonical:ubuntu_linux:16.04:*:*:*:esm:*:*:*

More vulnerabilities in Gnu Grub2

• CVE-2024-56737 — High (CVSS 8.8): GNU GRUB (aka GRUB2) through 2.12 has a heap-based buffer overflow in fs/hfs.c via crafted sblock data in an HFS…
• CVE-2022-2601 — High (CVSS 8.6): A buffer overflow was found in grub_font_construct_glyph(). A malicious crafted pf2 font can lead to an overflow when…
• CVE-2021-20233 — High (CVSS 8.2): A flaw was found in grub2 in versions prior to 2.06. Setparam_prefix() in the menu rendering code performs a length…
• CVE-2020-25632 — High (CVSS 8.2): A flaw was found in grub2 in versions prior to 2.06. The rmmod implementation allows the unloading of a module used as…
• CVE-2020-10713 — High (CVSS 8.2): A flaw was found in grub2, prior to version 2.06. An attacker may use the GRUB 2 flaw to hijack and tamper the GRUB…
• CVE-2022-28734 — High (CVSS 8.1): Out-of-bounds write when handling split HTTP headers; When handling split HTTP headers, GRUB2 HTTP code accidentally…

All CVEs affecting Gnu Grub2 →

Other CWE-362 (Race Condition) vulnerabilities

• CVE-2022-27626 — Critical (CVSS 10.0): A vulnerability regarding concurrent execution using shared resource with improper synchronization ('Race Condition')…
• CVE-2015-8556 — Critical (CVSS 10.0): Local privilege escalation vulnerability in the Gentoo QEMU package before 2.5.0-r1.
• CVE-2014-0703 — Critical (CVSS 10.0): Cisco Wireless LAN Controller (WLC) devices 7.4 before 7.4.110.0 distribute Aironet IOS software with a race condition…
• CVE-2010-1228 — Critical (CVSS 10.0): Multiple race conditions in the sandbox infrastructure in Google Chrome before 4.1.249.1036 have unspecified impact and…
• CVE-2008-6598 — Critical (CVSS 10.0): Multiple race conditions in WANPIPE before 3.3.6 have unknown impact and attack vectors related to "bri restart logic."
• CVE-2026-46137 — Critical (CVSS 9.8): In the Linux kernel, the following vulnerability has been resolved: mptcp: pm: ADD_ADDR rtx: fix potential…

Browse all CWE-362 (Race Condition) vulnerabilities →