CVE-2021-27097

The boot loader in Das U-Boot before 2021.04-rc2 mishandles a modified FIT.

Published: 2021-02-17 Last update: 2025-11-03 Assigner: [email protected] Source: [email protected]
NVD Status：Modified，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2021-27097 is rated Moderate Risk (53/100): CVSS High severity, with medium exploitation likelihood (EPSS 1.04%). Review affected assets and schedule remediation.

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-2021-27097

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 2026-06-15 0.05% 1.04% +0.99%
2 2026-02-27 0.05% 0.05% -0.00%
3 2025-11-21 — 0.05% —

Full EPSS history (11 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2021-27097

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
7.8 3.1 HIGH
CVSS:3.1/AV:L/AC:L/PR:N/UI:R/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:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:R)
A real person has to do something—click, install, enable—otherwise it doesn’t land.
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.
 1.8 5.9 [email protected]
7.8 3.1 HIGH
CVSS:3.1/AV:L/AC:L/PR:N/UI:R/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:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:R)
A real person has to do something—click, install, enable—otherwise it doesn’t land.
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.
 1.8 5.9 [email protected]
6.8 2.0 MEDIUM
AV:N/AC:M/Au:N/C:P/I:P/A:P Click to expand
Access vector (AV:N)
Can be exploited remotely over network reachability.
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.
 8.6 6.4 [email protected]

Weakness enumeration for CVE-2021-27097

OS Trackers for CVE-2021-27097

vendor priority summary link
alpine — CVE-2021-27097: 1 source package rows (u-boot); 10 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 0. https://security.alpinelinux.org/vuln/CVE-2021-27097
debian not yet assigned CVE-2021-27097 not yet assigned priority: Debian including 1 source packages (u-boot), 5 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): resolved 5. https://security-tracker.debian.org/tracker/CVE-2021-27097
suse medium CVE-2021-27097 severity moderate: SUSE including 3 source package names (u-boot, u-boot-rpi3, u-boot-tools), 48 product×package rows across 22 product lines (SUSE CaaS Platform 4.0, SUSE Enterprise Storage 6, … (22 product lines)): Known Not Affected 48. https://www.suse.com/security/cve/CVE-2021-27097/
ubuntu low CVE-2021-27097 low priority: Ubuntu including 1 source packages (u-boot), 10 status rows across 10 suites (bionic, focal, groovy, hirsute, impish, jammy, kinetic, trusty, upstream, xenial): ignored 5, not-affected 3, DNE 1, released 1. https://ubuntu.com/security/CVE-2021-27097

Affected software / configurations for CVE-2021-27097

Vendor Product Version Raw CPE
denx u-boot <= 2021.01 cpe:2.3:a:denx:u-boot:*:*:*:*:*:*:*:*
denx u-boot 2021.04 cpe:2.3:a:denx:u-boot:2021.04:rc1:*:*:*:*:*:*

References for CVE-2021-27097

cvelogic Threat Intelligence