Use After Free in GNU Grub2
CVE-2020-25632
A flaw was found in grub2 in versions prior to 2.06. The rmmod implementation allows the unloading of a module used as a dependency without checking if any other dependent module is still loaded leading to a use-after-free scenario. This could allow arbitrary code to be executed or a bypass of Secure Boot protections. The highest threat from this vulnerability is to data confidentiality and integrity as well as system availability.
Vulnerability class: Use-After-Free
Published · last modified .
CVSS v3 metric
CVSS v3 base score 8.2 (High). Vector: CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:H.
EPSS exploit prediction
EPSS: 0.012 (66.5th percentile), scored .
Low probability of exploitation in the next 30 days, but still tracked. 66th percentile — 66.5% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.012 · newest: 0.012 · change: 0.000
Affected products
- GNU Grub2
- NetApp Ontap Select Deploy Administration Utility
- Fedoraproject Fedora — versions 33, 34
- Red Hat Enterprise Linux — versions 7.0, 8.0
- Red Hat Enterprise Linux Server Aus — versions 7.2, 7.3, 7.4
- Red Hat Enterprise Linux Server Eus — versions 7.6, 7.7, 8.1
- Red Hat Enterprise Linux Server Tus — versions 7.4, 7.6, 7.7
- Red Hat Enterprise Linux Workstation — versions 7.0
- Grub2 — versions grub 2.06
Weakness classification (CWE)
Public proof-of-concept exploits
References
- bugzilla.redhat.com/show_bug.cgi (Patch, Third Party Advisory, Issue Tracking)
- lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/… (vendor-advisory)
- security.gentoo.org/glsa/202104-05 (vendor-advisory, Third Party Advisory)
- security.netapp.com/advisory/ntap-20220325-0001/ (Third Party Advisory)
Frequently asked questions
- What is CVE-2020-25632?
- CVE-2020-25632 is a high-severity vulnerability in GNU Grub2, classified under Use After Free. CVSS score: 8.2/10. Published 2021-03-03.
- How severe is CVE-2020-25632?
- High severity. CVSS v3 base score is 8.2 out of 10.
- Is CVE-2020-25632 known to be exploited?
- 26 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.