CVE-2021-3981 Information disclosure in grub2
Low 3.3
Published
Updated
Check this codebase for CVE-2021-3981 and fix it if it is affected.
What it is: CVE-2021-3981 is a low-severity vulnerability in Fedoraproject Fedora, published on 8 Mar 2022. It can only be exploited from the same machine or local network, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2021-3981 in the wild and no public exploit code.
Affected product: Fedoraproject Fedora. No package-level version data is available, so check the vendor advisory linked from the reference page.
Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.
Reference: https://insights.sbomify.com/CVE-2021-3981/ (Markdown: https://insights.sbomify.com/CVE-2021-3981/index.md)
Local attackers can read GRUB configuration files to obtain encrypted passwords due to incorrect file permissions.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2021-3981?
CVE-2021-3981 is a low-severity vulnerability in Fedoraproject Fedora, published on 8 Mar 2022. It can only be exploited from the same machine or local network, with no action from the victim.
Official description
A flaw in grub2 was found where its configuration file, known as grub.cfg, is being created with the wrong permission set allowing non privileged users to read its content. This represents a low severity confidentiality issue, as those users can eventually read any encrypted passwords present in grub.cfg. This flaw affects grub2 2.06 and previous versions. This issue has been fixed in grub upstream but no version with the fix is currently released.
Weakness: CWE-276
Which versions are affected by CVE-2021-3981?
It affects 2 products.
Linux distribution packages (40)
grub2-common AlmaLinux:8 | All versions | 1:2.02-123.el8.alma |
grub2-efi-aa64 AlmaLinux:8 | All versions | 1:2.02-123.el8.alma |
grub2-efi-aa64-cdboot AlmaLinux:8 | All versions | 1:2.02-123.el8.alma |
grub2-efi-aa64-modules AlmaLinux:8 | All versions | 1:2.02-123.el8.alma |
grub2-efi-ia32 AlmaLinux:8 | All versions | 1:2.02-123.el8.alma |
grub2-efi-ia32-cdboot AlmaLinux:8 | All versions | 1:2.02-123.el8.alma |
grub2-efi-ia32-modules AlmaLinux:8 | All versions | 1:2.02-123.el8.alma |
grub2-efi-x64 AlmaLinux:8 | All versions | 1:2.02-123.el8.alma |
grub2-efi-x64-cdboot AlmaLinux:8 | All versions | 1:2.02-123.el8.alma |
grub2-efi-x64-modules AlmaLinux:8 | All versions | 1:2.02-123.el8.alma |
grub2-pc AlmaLinux:8 | All versions | 1:2.02-123.el8.alma |
grub2-pc-modules AlmaLinux:8 | All versions | 1:2.02-123.el8.alma |
grub2-ppc64le AlmaLinux:8 | All versions | 1:2.02-123.el8_6.8.alma |
grub2-ppc64le-modules AlmaLinux:8 | All versions | 1:2.02-123.el8.alma |
grub2-tools AlmaLinux:8 | All versions | 1:2.02-123.el8.alma |
grub2-tools-efi AlmaLinux:8 | All versions | 1:2.02-123.el8.alma |
grub2-tools-extra AlmaLinux:8 | All versions | 1:2.02-123.el8.alma |
grub2-tools-minimal AlmaLinux:8 | All versions | 1:2.02-123.el8.alma |
grub2 Red Hat:enterprise_linux:8::baseos | All versions | 1:2.02-123.el8 |
grub2-common Red Hat:enterprise_linux:8::baseos | All versions | 1:2.02-123.el8 |
grub2-debuginfo Red Hat:enterprise_linux:8::baseos | All versions | 1:2.02-123.el8 |
grub2-debugsource Red Hat:enterprise_linux:8::baseos | All versions | 1:2.02-123.el8 |
grub2-efi-aa64 Red Hat:enterprise_linux:8::baseos | All versions | 1:2.02-123.el8 |
grub2-efi-aa64-cdboot Red Hat:enterprise_linux:8::baseos | All versions | 1:2.02-123.el8 |
grub2-efi-aa64-modules Red Hat:enterprise_linux:8::baseos | All versions | 1:2.02-123.el8 |
grub2-efi-ia32 Red Hat:enterprise_linux:8::baseos | All versions | 1:2.02-123.el8 |
grub2-efi-ia32-cdboot Red Hat:enterprise_linux:8::baseos | All versions | 1:2.02-123.el8 |
grub2-efi-ia32-modules Red Hat:enterprise_linux:8::baseos | All versions | 1:2.02-123.el8 |
grub2-efi-x64 Red Hat:enterprise_linux:8::baseos | All versions | 1:2.02-123.el8 |
grub2-efi-x64-cdboot Red Hat:enterprise_linux:8::baseos | All versions | 1:2.02-123.el8 |
grub2-efi-x64-modules Red Hat:enterprise_linux:8::baseos | All versions | 1:2.02-123.el8 |
grub2-pc Red Hat:enterprise_linux:8::baseos | All versions | 1:2.02-123.el8 |
grub2-pc-modules Red Hat:enterprise_linux:8::baseos | All versions | 1:2.02-123.el8 |
grub2-ppc64le Red Hat:enterprise_linux:8::baseos | All versions | 1:2.02-123.el8 |
grub2-ppc64le-modules Red Hat:enterprise_linux:8::baseos | All versions | 1:2.02-123.el8 |
grub2-tools Red Hat:enterprise_linux:8::baseos | All versions | 1:2.02-123.el8 |
grub2-tools-debuginfo Red Hat:enterprise_linux:8::baseos | All versions | 1:2.02-123.el8 |
grub2-tools-efi Red Hat:enterprise_linux:8::baseos | All versions | 1:2.02-123.el8 |
grub2-tools-efi-debuginfo Red Hat:enterprise_linux:8::baseos | All versions | 1:2.02-123.el8 |
grub2-tools-extra Red Hat:enterprise_linux:8::baseos | All versions | 1:2.02-123.el8 |
Products include Fedoraproject Fedora, Gnu Grub2.
How do I fix CVE-2021-3981?
No fix published yet.
Is CVE-2021-3981 being exploited?
There is no known exploitation of CVE-2021-3981 in the wild and no public exploit code.
Other vulnerabilities in Fedoraproject Fedora
Sources
Also known as ALSA-2022:2110, AZL-34786, AZL-8937, DEBIAN-CVE-2021-3981, GHSA-6hfm-rxpf-979r, OESA-2022-1597 and 4 more.