CVE-2021-3696: Medium severity GNU GRUB2 vulnerability
A flaw was found in grub2 when handling a PNG image header. When decoding the data contained in the Huffman table at the PNG file header, an out-of-bounds write may happen on grub's heap.
Other sources
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.
Affected Software
Remediation
Recommended actions to resolve this vulnerability, in priority order.
- Upgrade
Upgrade
debian/grub2to a version that resolves this vulnerability.Fixed in 2.06-3~deb10u1Fixed in 2.06-3~deb10u3Fixed in 2.06-3~deb11u5Fixed in 2.06-3~deb11u4Fixed in 2.06-13Fixed in 2.12~rc1-9 - Upgrade
Upgrade
redhat/grub2to a version that resolves this vulnerability.Fixed in 1:2.02-123.el8_6.8 - Upgrade
Upgrade
redhat/grub2to a version that resolves this vulnerability.Fixed in 1:2.02-87.el8_1.10 - Upgrade
Upgrade
redhat/grub2to a version that resolves this vulnerability.Fixed in 1:2.02-87.el8_2.10 - Upgrade
Upgrade
redhat/grub2to a version that resolves this vulnerability.Fixed in 1:2.02-99.el8_4.9 - Upgrade
Upgrade
redhat/grub2to a version that resolves this vulnerability.Fixed in 1:2.06-27.el9_0.7 - Upgrade
Upgrade
redhat/grubto a version that resolves this vulnerability.Fixed in 2.12 - Upgrade
Upgrade
grub2to a version that resolves this vulnerability.Fixed in grub-2.12
Event History
Parent advisories
This vulnerability appears in the following advisories.
Frequently Asked Questions
What is CVE-2021-3696?
CVE-2021-3696 is a vulnerability found in grub2 when handling a PNG image header, which can lead to data corruption in the heap space.
What is the severity of CVE-2021-3696?
The severity of CVE-2021-3696 is medium with a severity value of 5.
What software is affected by CVE-2021-3696?
The affected software includes grub2 versions 1:2.02-123.el8_6.8, 1:2.02-87.el8_1, 1:2.02-87.el8_2, 1:2.02-99.el8_4.9, and 1:2.06-27.el9_0.7.
How can I fix CVE-2021-3696?
You can fix CVE-2021-3696 by applying the recommended patches provided by Redhat.
Where can I find more information about CVE-2021-3696?
You can find more information about CVE-2021-3696 on the CVE website (https://www.cve.org/CVERecord?id=CVE-2021-3696) and NIST NVD (https://nvd.nist.gov/vuln/detail/CVE-2021-3696).