CVE-2020-14309

There's an issue with grub2 in all versions before 2.06 when handling squashfs filesystems containing a symbolic link with name length of UINT32 bytes in size. The name size leads to an arithmetic overflow leading to a zero-size allocation further causing a heap-based buffer overflow with attacker controlled data.

Published: 2020-07-30 Last update: 2026-06-16 Assigner: [email protected] Source: [email protected]
NVD Status：Modified，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2020-14309 is rated Moderate Risk (40.5/100): CVSS Medium severity, with low exploitation likelihood (EPSS 0.49%). 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-2020-14309

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 0.04% 0.49% +0.44%
2 2025-11-21 0.10% 0.04% -0.05%
3 2025-11-18 — 0.10% —

Full EPSS history (12 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2020-14309

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]
4.6 2.0 MEDIUM
AV:L/AC:L/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:L)
Exploitation conditions are straightforward and predictable.
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.
 3.9 6.4 [email protected]

Weakness enumeration for CVE-2020-14309

OS Trackers for CVE-2020-14309

vendor priority summary link
alpine medium CVE-2020-14309: 1 source package rows (grub); 7 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 7, open 0. https://security.alpinelinux.org/vuln/CVE-2020-14309
debian not yet assigned CVE-2020-14309 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-2020-14309
gentoo normal CVE-2020-14309: 1 GLSA(s) (202104-05), 1 atom(s) (sys-devel/grub); latest impact normal. https://bugs.gentoo.org/buglist.cgi?quicksearch=CVE-2020-14309
redhat medium — https://access.redhat.com/security/cve/CVE-2020-14309
suse medium CVE-2020-14309 severity moderate: SUSE including 200 source package names (grub2-2.02-12.31.1, grub2-2.02-19.48.1, …), 432 product×package rows across 75 product lines (HPE Helion OpenStack 8, Image SLES12-SP5-Azure-BYOS, … (75 product lines)): Fixed 432. https://www.suse.com/security/cve/CVE-2020-14309/
ubuntu high CVE-2020-14309 high priority: Ubuntu including 3 source packages (grub2, grub2-signed, grub2-unsigned), 44 status rows across 16 suites (bionic, eoan, focal, groovy, hirsute, jammy, kinetic, lunar, mantic, noble, oracular, plucky, questing, trusty, upstream, xenial): not-affected 28, released 10, needs-triage 3, DNE 1, ignored 1, needed 1. https://ubuntu.com/security/CVE-2020-14309

Affected software / configurations for CVE-2020-14309

Vendor Product Version Raw CPE
gnu grub2 < 2.06 cpe:2.3:a:gnu:grub2:*:*:*:*:*:*:*:*
opensuse leap 15.1 cpe:2.3:o:opensuse:leap:15.1:*:*:*:*:*:*:*
opensuse leap 15.2 cpe:2.3:o:opensuse:leap:15.2:*:*:*:*:*:*:*

References for CVE-2020-14309

cvelogic Threat Intelligence