Buffer overflow in GNU Grub2
CVE-2021-3696
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.
Vulnerability class: Buffer Overflow
Published · last modified .
CVSS v3 metric
CVSS v3 base score 4.5 (Medium). Vector: CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:L/I:L/A:L.
EPSS exploit prediction
EPSS: 0.005 (39.6th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 40th percentile — 39.6% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.005 · newest: 0.005 · change: 0.000
Affected products
- GNU Grub2
- NetApp Ontap Select Deploy Administration Utility
- Red Hat Codeready Linux Builder
- Red Hat Developer Tools — versions 1.0
- Red Hat Enterprise Linux — versions 8.0, 8.1, 8.4
- Red Hat Enterprise Linux Eus — versions 8.2, 8.4, 8.6
- Red Hat Enterprise Linux For Power Little Endian — versions 8.0, 9.0
- Red Hat Enterprise Linux For Power Little Endian Eus — versions 8.2, 8.4, 8.6
- Red Hat Enterprise Linux Server Aus — versions 8.2, 8.4, 8.6
- Red Hat Enterprise Linux Server For Power Little Endian Update Services SAP Solutions — versions 8.1, 8.2, 8.4
Weakness classification (CWE)
Public proof-of-concept exploits
References
- bugzilla.redhat.com/show_bug.cgi (Third Party Advisory, Issue Tracking)
- security.gentoo.org/glsa/202209-12 (vendor-advisory, Third Party Advisory)
- security.netapp.com/advisory/ntap-20220930-0001/ (Third Party Advisory)
Frequently asked questions
- What is CVE-2021-3696?
- CVE-2021-3696 is a medium-severity vulnerability in GNU Grub2, classified under Out-of-bounds Write. CVSS score: 4.5/10. Published 2022-07-06.
- How severe is CVE-2021-3696?
- Medium severity. CVSS v3 base score is 4.5 out of 10.
- Is CVE-2021-3696 known to be exploited?
- 18 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.