Vulnerability · Published Jul 6, 2022 · Assigned by redhat
CVE-2021-3696
Medium 4.5
In plain English
A medium-severity out-of-bounds write in grub2. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.5% (higher than 42% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.
Severity (CVSS NVD)4.5Medium
Exploit odds (30 days)0.5%top 58.1% of all CVEs
Exploited in the wildNo reportsnot in CISA KEV
Attack toolingNoneno public tooling known
Official description
A heap out-of-bounds write may heppen during the handling of Huffman tables in the PNG reader. This may lead to data corruption in the heap space. Confidentiality, Integrity and Availablity impact may be considered Low as it's very complex to an attacker control the encoding and positioning of corrupted Huffman entries to achieve results such as arbitrary code execution and/or secure boot circumvention. This flaw affects grub2 versions prior grub-2.12.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| AlmaLinux:8 | grub2-common | 1:2.02-123.el8_6.8.alma | ALSA-2022:5095 |
| AlmaLinux:9 | grub2-common | 1:2.06-27.el9_0.7.alma | ALSA-2022:5099 |
| AlmaLinux:8 | grub2-efi-aa64 | 1:2.02-123.el8_6.8.alma | ALSA-2022:5095 |
| AlmaLinux:9 | grub2-efi-aa64 | 1:2.06-27.el9_0.7.alma | ALSA-2022:5099 |
| AlmaLinux:8 | grub2-efi-aa64-cdboot | 1:2.02-123.el8_6.8.alma | ALSA-2022:5095 |
| AlmaLinux:9 | grub2-efi-aa64-cdboot | 1:2.06-27.el9_0.7.alma | ALSA-2022:5099 |
| AlmaLinux:8 | grub2-efi-aa64-modules | 1:2.02-123.el8_6.8.alma | ALSA-2022:5095 |
| AlmaLinux:9 | grub2-efi-aa64-modules | 1:2.06-27.el9_0.7.alma | ALSA-2022:5099 |
| AlmaLinux:8 | grub2-efi-ia32 | 1:2.02-123.el8_6.8.alma | ALSA-2022:5095 |
| AlmaLinux:8 | grub2-efi-ia32-cdboot | 1:2.02-123.el8_6.8.alma | ALSA-2022:5095 |
| AlmaLinux:8 | grub2-efi-ia32-modules | 1:2.02-123.el8_6.8.alma | ALSA-2022:5095 |
| AlmaLinux:8 | grub2-efi-x64 | 1:2.02-123.el8_6.8.alma | ALSA-2022:5095 |
| AlmaLinux:9 | grub2-efi-x64 | 1:2.06-27.el9_0.7.alma | ALSA-2022:5099 |
| AlmaLinux:8 | grub2-efi-x64-cdboot | 1:2.02-123.el8_6.8.alma | ALSA-2022:5095 |
| AlmaLinux:9 | grub2-efi-x64-cdboot | 1:2.06-27.el9_0.7.alma | ALSA-2022:5099 |
| AlmaLinux:8 | grub2-efi-x64-modules | 1:2.02-123.el8_6.8.alma | ALSA-2022:5095 |
| AlmaLinux:9 | grub2-efi-x64-modules | 1:2.06-27.el9_0.7.alma | ALSA-2022:5099 |
| AlmaLinux:8 | grub2-pc | 1:2.02-123.el8_6.8.alma | ALSA-2022:5095 |
| AlmaLinux:9 | grub2-pc | 1:2.06-27.el9_0.7.alma | ALSA-2022:5099 |
| AlmaLinux:8 | grub2-pc-modules | 1:2.02-123.el8_6.8.alma | ALSA-2022:5095 |
| AlmaLinux:9 | grub2-pc-modules | 1:2.06-27.el9_0.7.alma | ALSA-2022:5099 |
| AlmaLinux:9 | grub2-ppc64le | 1:2.06-27.el9_0.7.alma | ALSA-2022:5099 |
| AlmaLinux:8 | grub2-ppc64le-modules | 1:2.02-123.el8_6.8.alma | ALSA-2022:5095 |
| AlmaLinux:9 | grub2-ppc64le-modules | 1:2.06-27.el9_0.7.alma | ALSA-2022:5099 |
| AlmaLinux:8 | grub2-tools | 1:2.02-123.el8_6.8.alma | ALSA-2022:5095 |
| AlmaLinux:9 | grub2-tools | 1:2.06-27.el9_0.7.alma | ALSA-2022:5099 |
| AlmaLinux:8 | grub2-tools-efi | 1:2.02-123.el8_6.8.alma | ALSA-2022:5095 |
| AlmaLinux:9 | grub2-tools-efi | 1:2.06-27.el9_0.7.alma | ALSA-2022:5099 |
| AlmaLinux:8 | grub2-tools-extra | 1:2.02-123.el8_6.8.alma | ALSA-2022:5095 |
| AlmaLinux:9 | grub2-tools-extra | 1:2.06-27.el9_0.7.alma | ALSA-2022:5099 |
| AlmaLinux:8 | grub2-tools-minimal | 1:2.02-123.el8_6.8.alma | ALSA-2022:5095 |
| AlmaLinux:9 | grub2-tools-minimal | 1:2.06-27.el9_0.7.alma | ALSA-2022:5099 |
| AlmaLinux:8 | shim-aa64 | 15.6-1.el8.alma | ALSA-2022:5095 |
| AlmaLinux:9 | shim-aa64 | 15.6-1.el9.alma | ALSA-2022:5099 |
| AlmaLinux:8 | shim-ia32 | 15.6-1.el8.alma | ALSA-2022:5095 |
| AlmaLinux:8 | shim-unsigned-x64 | 15.6-1.el8.alma | ALSA-2022:5095 |
| AlmaLinux:9 | shim-unsigned-x64 | 15.6-1.el9.alma | ALSA-2022:5099 |
| AlmaLinux:8 | shim-x64 | 15.6-1.el8.alma | ALSA-2022:5095 |
| AlmaLinux:9 | shim-x64 | 15.6-1.el9.alma | ALSA-2022:5099 |
| Debian:12 | grub2 | 2.06-3 | DEBIAN-CVE-2021-3696 |
| Debian:13 | grub2 | 2.06-3 | DEBIAN-CVE-2021-3696 |
| Debian:14 | grub2 | 2.06-3 | DEBIAN-CVE-2021-3696 |
| Rocky Linux:8 | grub2 | 1:2.02-123.el8_6.8 | RLSA-2022:5095 |
| Rocky Linux:8 | mokutil | 1:0.3.0-11.el8_6.1 | RLSA-2022:5095 |
| Rocky Linux:9 | mokutil | 2:0.4.0-8.el9_0.1 | RLSA-2022:5099 |
| Rocky Linux:8 | shim | 0:15.6-1.el8 | RLSA-2022:5095 |
| Rocky Linux:9 | shim | 0:15.6-1.el9 | RLSA-2022:5099 |
| Rocky Linux:9 | shim | 0:15.6-1.el9.rocky.0.1 | RLSA-2022:5099 |
| Rocky Linux:8 | shim-unsigned-x64 | 0:15.6-1.el8 | RLSA-2022:5095 |
| Ubuntu:22.04:LTS | grub2-signed | 1.187.3~22.04.1 | USN-6355-1 |
| Ubuntu:22.04:LTS | grub2-signed | 1.187.3~22.04.1 | UBUNTU-CVE-2021-3696 |
| Ubuntu:22.04:LTS | grub2-unsigned | 2.06-2ubuntu14.1 | UBUNTU-CVE-2021-3696 |
| Ubuntu:22.04:LTS | grub2-unsigned | 2.06-2ubuntu14.1 | USN-6355-1 |
| Ubuntu:22.04:LTS | shim | 15.7-0ubuntu1 | USN-6355-1 |
| Ubuntu:22.04:LTS | shim-signed | 1.51.3 | USN-6355-1 |
Affected products (as reported)
Weakness: CWE-787
References
- https://bugzilla.redhat.com/show_bug.cgi?id=1991686 x_refsource_MISC
- GLSA-202209-12 vendor-advisory, x_refsource_GENTOO
- https://security.netapp.com/advisory/ntap-20220930-0001/ x_refsource_CONFIRM