CVE-2021-3697

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.

Published: 2022-07-06 Last update: 2024-11-21 Assigner: [email protected] Source: [email protected]
NVD Status：Modified，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2021-3697 is rated Low Risk (34/100): CVSS High severity, with low exploitation likelihood (EPSS 0.07%). Monitor for updates and reassess as exploit intelligence or EPSS changes.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2021-3697

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2025-03-30 0.17% 0.07% -0.11%
2 2025-03-29 0.07% 0.17% +0.11%
3 2025-03-17 — 0.07% —

Full EPSS history (7 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2021-3697

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
7.0 3.1 HIGH
CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H Click to expand
Attack vector (AV:L)
They already need access on the box, or another person has to do something wrong; it’s not a remote drive-by.
Attack complexity (AC:H)
Even with access, the exploit needs extra luck, timing, or a fussy environment to actually work.
Privileges required (PR:L)
A normal user session is enough; they don’t have to be admin.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:H)
Serious risk that confidential data gets exposed in a big way.
Integrity (I:H)
They could widely tamper with or forge data—trust in the data is badly hurt.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
 1.0 5.9 [email protected]
4.4 2.0 MEDIUM
AV:L/AC:M/Au:N/C:P/I:P/A:P Click to expand
Access vector (AV:L)
Requires local access to the target system.
Access complexity (AC:M)
Exploitation needs some favorable conditions, but not exceptional ones.
Authentication (AU:N)
No authentication is required.
Confidentiality impact (C:P)
Partial confidentiality impact.
Integrity impact (I:P)
Partial integrity impact.
Availability impact (A:P)
Partial availability impact.
 3.4 6.4 [email protected]

Weakness enumeration for CVE-2021-3697

OS Trackers for CVE-2021-3697

vendor priority summary link
alpine high CVE-2021-3697: 1 source package rows (grub); 15 state rows across 7 repos (3.17-main, 3.18-main, 3.19-main, 3.20-main, 3.21-main, 3.22-main, edge-main); fixed 10, open 5. https://security.alpinelinux.org/vuln/CVE-2021-3697
debian not yet assigned CVE-2021-3697 not yet assigned priority: Debian including 1 source packages (grub2), 5 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): resolved 5. https://security-tracker.debian.org/tracker/CVE-2021-3697
gentoo high CVE-2021-3697: 1 GLSA(s) (202209-12), 1 atom(s) (sys-boot/grub); latest impact high. https://bugs.gentoo.org/buglist.cgi?quicksearch=CVE-2021-3697
redhat medium — https://access.redhat.com/security/cve/CVE-2021-3697
suse high — https://www.suse.com/security/cve/CVE-2021-3697/
ubuntu medium CVE-2021-3697 medium priority: Ubuntu including 3 source packages (grub2, grub2-signed, grub2-unsigned), 40 status rows across 14 suites (bionic, focal, impish, jammy, kinetic, lunar, mantic, noble, oracular, plucky, questing, trusty, upstream, xenial): not-affected 24, released 6, ignored 3, needed 3, needs-triage 3, DNE 1. https://ubuntu.com/security/CVE-2021-3697

Affected software / configurations for CVE-2021-3697

Vendor Product Version Raw CPE
gnu grub2 >= 2.00, < 2.12 cpe:2.3:a:gnu:grub2:*:*:*:*:*:*:*:*
redhat developer_tools 1.0 cpe:2.3:a:redhat:developer_tools:1.0:*:*:*:*:*:*:*
redhat openshift 3.0 cpe:2.3:a:redhat:openshift:3.0:*:*:*:*:*:*:*
redhat enterprise_linux 8.0 cpe:2.3:o:redhat:enterprise_linux:8.0:*:*:*:*:*:*:*
redhat enterprise_linux 8.1 cpe:2.3:o:redhat:enterprise_linux:8.1:*:*:*:*:*:*:*
redhat enterprise_linux 8.4 cpe:2.3:o:redhat:enterprise_linux:8.4:*:*:*:*:*:*:*
redhat enterprise_linux 9.0 cpe:2.3:o:redhat:enterprise_linux:9.0:*:*:*:*:*:*:*
redhat enterprise_linux_eus 8.2 cpe:2.3:o:redhat:enterprise_linux_eus:8.2:*:*:*:*:*:*:*
redhat enterprise_linux_eus 8.4 cpe:2.3:o:redhat:enterprise_linux_eus:8.4:*:*:*:*:*:*:*
redhat enterprise_linux_eus 8.6 cpe:2.3:o:redhat:enterprise_linux_eus:8.6:*:*:*:*:*:*:*
redhat enterprise_linux_eus 9.0 cpe:2.3:o:redhat:enterprise_linux_eus:9.0:*:*:*:*:*:*:*
redhat enterprise_linux_for_power_little_endian 8.0 cpe:2.3:o:redhat:enterprise_linux_for_power_little_endian:8.0:*:*:*:*:*:*:*
redhat enterprise_linux_for_power_little_endian 9.0 cpe:2.3:o:redhat:enterprise_linux_for_power_little_endian:9.0:*:*:*:*:*:*:*
redhat enterprise_linux_for_power_little_endian_eus 8.2 cpe:2.3:o:redhat:enterprise_linux_for_power_little_endian_eus:8.2:*:*:*:*:*:*:*
redhat enterprise_linux_for_power_little_endian_eus 8.4 cpe:2.3:o:redhat:enterprise_linux_for_power_little_endian_eus:8.4:*:*:*:*:*:*:*
redhat enterprise_linux_for_power_little_endian_eus 8.6 cpe:2.3:o:redhat:enterprise_linux_for_power_little_endian_eus:8.6:*:*:*:*:*:*:*
redhat enterprise_linux_for_power_little_endian_eus 9.0 cpe:2.3:o:redhat:enterprise_linux_for_power_little_endian_eus:9.0:*:*:*:*:*:*:*
redhat enterprise_linux_server_aus 8.2 cpe:2.3:o:redhat:enterprise_linux_server_aus:8.2:*:*:*:*:*:*:*
redhat enterprise_linux_server_aus 8.4 cpe:2.3:o:redhat:enterprise_linux_server_aus:8.4:*:*:*:*:*:*:*
redhat enterprise_linux_server_aus 8.6 cpe:2.3:o:redhat:enterprise_linux_server_aus:8.6:*:*:*:*:*:*:*
redhat enterprise_linux_server_for_power_little_endian_update_services_for_sap_solutions 8.1 cpe:2.3:o:redhat:enterprise_linux_server_for_power_little_endian_update_services_for_sap_solutions:8.1:*:*:*:*:*:*:*
redhat enterprise_linux_server_for_power_little_endian_update_services_for_sap_solutions 8.2 cpe:2.3:o:redhat:enterprise_linux_server_for_power_little_endian_update_services_for_sap_solutions:8.2:*:*:*:*:*:*:*
redhat enterprise_linux_server_for_power_little_endian_update_services_for_sap_solutions 8.4 cpe:2.3:o:redhat:enterprise_linux_server_for_power_little_endian_update_services_for_sap_solutions:8.4:*:*:*:*:*:*:*
redhat enterprise_linux_server_for_power_little_endian_update_services_for_sap_solutions 8.6 cpe:2.3:o:redhat:enterprise_linux_server_for_power_little_endian_update_services_for_sap_solutions:8.6:*:*:*:*:*:*:*
redhat enterprise_linux_server_for_power_little_endian_update_services_for_sap_solutions 9.0 cpe:2.3:o:redhat:enterprise_linux_server_for_power_little_endian_update_services_for_sap_solutions:9.0:*:*:*:*:*:*:*
redhat enterprise_linux_server_tus 8.2 cpe:2.3:o:redhat:enterprise_linux_server_tus:8.2:*:*:*:*:*:*:*
redhat enterprise_linux_server_tus 8.4 cpe:2.3:o:redhat:enterprise_linux_server_tus:8.4:*:*:*:*:*:*:*
redhat enterprise_linux_server_tus 8.6 cpe:2.3:o:redhat:enterprise_linux_server_tus:8.6:*:*:*:*:*:*:*
redhat openshift_container_platform 4.6 cpe:2.3:a:redhat:openshift_container_platform:4.6:*:*:*:*:*:*:*
redhat openshift_container_platform 4.9 cpe:2.3:a:redhat:openshift_container_platform:4.9:*:*:*:*:*:*:*
redhat openshift_container_platform 4.10 cpe:2.3:a:redhat:openshift_container_platform:4.10:*:*:*:*:*:*:*
redhat codeready_linux_builder — cpe:2.3:a:redhat:codeready_linux_builder:-:*:*:*:*:*:*:*

References for CVE-2021-3697

cvelogic Threat Intelligence