CVE-2024-56738

GNU GRUB (aka GRUB2) through 2.12 does not use a constant-time algorithm for grub_crypto_memcmp and thus allows side-channel attacks.

Published: 2024-12-29 Last update: 2025-06-24 Assigner: [email protected] Source: [email protected]
NVD Status：Analyzed，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2024-56738 is rated Low Risk (23.7/100): CVSS Medium severity, with low exploitation likelihood (EPSS 0.03%). 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-2024-56738

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 2026-02-06 0.13% 0.03% -0.10%
2 2025-11-21 0.17% 0.13% -0.04%
3 2025-11-18 — 0.17% —

Full EPSS history (9 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2024-56738

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
5.3 3.1 MEDIUM
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
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: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:L)
Some sensitive info could get out, but not a total data dump.
Integrity (I:N)
Data isn’t meaningfully altered or forged.
Availability (A:N)
Service keeps running; no real outage angle.
 3.9 1.4 134c704f-9b21-4f2e-91b3-4a467353bcc0

Weakness enumeration for CVE-2024-56738

OS Trackers for CVE-2024-56738

vendor priority summary link
debian not yet assigned CVE-2024-56738 not yet assigned priority: Debian including 1 source packages (grub2), 5 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): open 5. https://security-tracker.debian.org/tracker/CVE-2024-56738
redhat medium — https://access.redhat.com/security/cve/CVE-2024-56738
suse medium — https://www.suse.com/security/cve/CVE-2024-56738/
ubuntu medium CVE-2024-56738 medium priority: Ubuntu including 3 source packages (grub2, grub2-signed, grub2-unsigned), 29 status rows across 10 suites (bionic, focal, jammy, noble, oracular, plucky, questing, trusty, upstream, xenial): needs-triage 15, not-affected 8, ignored 6. https://ubuntu.com/security/CVE-2024-56738

Affected software / configurations for CVE-2024-56738

Vendor Product Version Raw CPE
gnu grub2 <= 2.12 cpe:2.3:a:gnu:grub2:*:*:*:*:*:*:*:*

References for CVE-2024-56738

URL Tags
https://savannah.gnu.org/bugs/?66603 Issue Tracking Third Party Advisory
cvelogic Threat Intelligence