CVE-2021-3981
First published: Wed Nov 17 2021(Updated: )
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.
Credit: secalert@redhat.com secalert@redhat.com secalert@redhat.com
| Affected Software | Affected Version | How to fix |
|---|---|---|
| <=2.06 | ||
| =34 | ||
| Gnu Grub2 | <=2.06 | |
| Fedoraproject Fedora | =34 | |
| debian/grub2 | <=2.06-3~deb10u1<=2.06-3~deb10u3<=2.06-3~deb11u5<=2.06-3~deb11u4 | 2.06-13 2.12~rc1-9 |
Remedy
https://git.savannah.gnu.org/gitweb/?p=grub.git;a=commit;h=0adec29674561034771c13e446069b41ef41e4d4
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Reference Links
- https://bugzilla.redhat.com/show_bug.cgi?id=2024170
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/AI776L35DDYPCSAAJPJM3ZEQYSFZHBJX/
- https://security.gentoo.org/glsa/202209-12
- https://launchpad.net/bugs/cve/CVE-2021-3981
- http://www.openwall.com/lists/oss-security/2024/01/15/3
- https://bugzilla.redhat.com/show_bug.cgi/show_bug.cgi?id=2030358
- https://git.savannah.gnu.org/cgit/grub.git/commit/?id=0adec29674561034771c13e446069b41ef41e4d4
- https://access.redhat.com/errata/RHSA-2022:2110
- https://access.redhat.com/security/cve/cve-2021-3981
- https://git.savannah.gnu.org/gitweb/?p=grub.git;a=commit;h=ab2e53c8a196a595e50f1c836bf756b9db1ae68d
- https://lists.gnu.org/archive/html/grub-devel/2021-12/msg00013.html
- https://git.savannah.gnu.org/gitweb/?p=grub.git;a=commit;h=0adec29674561034771c13e446069b41ef41e4d4
- https://security-tracker.debian.org/tracker/CVE-2021-3981
- https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2021-3981
- https://access.redhat.com/security/cve/CVE-2021-3981
- https://nvd.nist.gov/vuln/detail/CVE-2021-3981
- https://ubuntu.com/security/CVE-2021-3981
Frequently Asked Questions
What is CVE-2021-3981?
CVE-2021-3981 is a vulnerability in grub2 where its configuration file (grub.cfg) is created with the wrong permissions, allowing non-privileged users to read its content.
What is the severity of CVE-2021-3981?
CVE-2021-3981 has a low severity rating.
How can non-privileged users exploit CVE-2021-3981?
Non-privileged users can exploit CVE-2021-3981 by reading the content of the grub.cfg file, which may contain encrypted passwords.
How can I fix CVE-2021-3981?
To fix CVE-2021-3981, update the grub2 package to version 2.06-13 or 2.12~rc1-9, as recommended by Debian.
Where can I find more information about CVE-2021-3981?
You can find more information about CVE-2021-3981 on the MITRE CVE website, the Red Hat security website, and the NIST National Vulnerability Database.
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