CVE-2021-3697

Severity: high (CVSS 7.0 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.5% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2022-07-06 · updated 2026-06-17
Weakness: CWE-787

Description

A crafted JPEG image may lead the JPEG reader to underflow its data pointer, allowing user-controlled data to be written in heap. To a successful to be performed the attacker needs to perform some triage over the heap layout and craft an image with a malicious format and payload. This vulnerability can lead to data corruption and eventual code execution or secure boot circumvention. This flaw affects grub2 versions prior grub-2.12.

Affected products

grub2: from 2.00 before 2.12 — fixed in 2.12
RedHat Codeready Linux Builder: all versions
RedHat Developer Tools: 1.0
Red Hat Enterprise Linux: 8.0, 8.1, 8.4, 9.0
RedHat Enterprise Linux Eus: 8.2, 8.4, 8.6, 9.0
RedHat Enterprise Linux For Power Little Endian: 8.0, 9.0
RedHat Enterprise Linux For Power Little Endian Eus: 8.2, 8.4, 8.6, 9.0
RedHat Enterprise Linux Server Aus: 8.2, 8.4, 8.6
RedHat Enterprise Linux Server For Power Little Endian Update Services For Sap Solutions: 8.1, 8.2, 8.4, 8.6, 9.0
RedHat Enterprise Linux Server Tus: 8.2, 8.4, 8.6
Openshift: 3.0
Red Hat OpenShift Container Platform 4.18: 4.6, 4.9, 4.10

How to fix

Upgrade to a fixed version: grub2 2.12. Check the vendor advisory for mitigations.

References

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