Buffer overflow in GNU Grub2
CVE-2021-20233
A flaw was found in grub2 in versions prior to 2.06. Setparam_prefix() in the menu rendering code performs a length calculation on the assumption that expressing a quoted single quote will require 3 characters, while it actually requires 4 characters which allows an attacker to corrupt memory by one byte for each quote in the input. The highest threat from this vulnerability is to data confidentiality and integrity as well as system availability.
Vulnerability class: Buffer Overflow
EPSS: 0.006 (46.7th percentile) — read the EPSS interpretation.
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.
Affected products
- Gnu Grub2
- Netapp Ontap_select_deploy_administration_utility
- Fedoraproject Fedora — versions 33, 34
- Redhat Enterprise_linux — versions 7.0, 8.0
- Redhat Enterprise_linux_server_aus — versions 7.2, 7.3, 7.4
- Redhat Enterprise_linux_server_eus — versions 7.6, 7.7, 8.1
- Redhat Enterprise_linux_server_tus — versions 7.4, 7.6, 7.7
- Redhat Enterprise_linux_workstation — versions 7.0
- N/a Grub2 — versions grub 2.06
Weakness classification (CWE)
Public proof-of-concept exploits
References
- secalert@redhat.com (Patch, Third Party Advisory, x_refsource_MISC, Issue Tracking)
- secalert@redhat.com (x_refsource_FEDORA, vendor-advisory)
- secalert@redhat.com (vendor-advisory, Third Party Advisory, x_refsource_GENTOO)
- secalert@redhat.com (x_refsource_CONFIRM, Third Party Advisory)
Frequently asked questions
- What is CVE-2021-20233?
- CVE-2021-20233 is a high-severity vulnerability in GNU Grub2, classified under Out-of-bounds Write. CVSS score: 8.2/10. Published 2021-03-03.
- How severe is CVE-2021-20233?
- High severity. CVSS v3 base score is 8.2 out of 10.
- Is CVE-2021-20233 known to be exploited?
- 36 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.