CVE-2023-49721

An insecure default to allow UEFI Shell in EDK2 was left enabled in LXD. This allows an OS-resident attacker to bypass Secure Boot.

Published: 2024-02-14 Last update: 2025-08-26 Assigner: [email protected] Source: [email protected]
NVD Status：Analyzed，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2023-49721 is rated Low Risk (27.8/100): CVSS Medium severity, with low exploitation likelihood (EPSS 0.02%). 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-2023-49721

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 2025-11-21 0.06% 0.02% -0.04%
2 2025-11-18 0.01% 0.06% +0.04%
3 2025-04-15 — 0.01% —

Full EPSS history (5 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2023-49721

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
6.7 3.1 MEDIUM
CVSS:3.1/AV:L/AC:L/PR:H/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:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:H)
They need powerful rights—admin, root, or similar—before this pays off.
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.
 0.8 5.9 [email protected]

Weakness enumeration for CVE-2023-49721

OS Trackers for CVE-2023-49721

vendor priority summary link
alpine — CVE-2023-49721: 2 source package rows (edk2, lxd); 13 state rows across 3 repos (3.22-community, 3.23-community, edge-community); fixed 0, open 13. https://security.alpinelinux.org/vuln/CVE-2023-49721
debian unimportant CVE-2023-49721 unimportant priority: Debian including 2 source packages (incus, lxd), 5 status rows across 4 suites (bookworm, forky, sid, trixie): resolved 5. https://security-tracker.debian.org/tracker/CVE-2023-49721
suse medium — https://www.suse.com/security/cve/CVE-2023-49721/
ubuntu medium CVE-2023-49721 medium priority: Ubuntu including 1 source packages (lxd), 9 status rows across 9 suites (bionic, focal, jammy, lunar, mantic, noble, trusty, upstream, xenial): DNE 4, not-affected 3, ignored 1, needs-triage 1. https://ubuntu.com/security/CVE-2023-49721

Affected software / configurations for CVE-2023-49721

Vendor Product Version Raw CPE
canonical lxd >= 5.0.0, < 5.21.0 cpe:2.3:a:canonical:lxd:*:*:*:*:*:*:*:*
tianocore edk2 <= 2023.11-8 cpe:2.3:a:tianocore:edk2:*:-:*:*:*:*:*:*

References for CVE-2023-49721

cvelogic Threat Intelligence