CVE-2021-20316

A flaw was found in the way Samba handled file/directory metadata. This flaw allows an authenticated attacker with permissions to read or modify share metadata, to perform this operation outside of the share.

Published: 2022-08-23 Last update: 2026-06-16 Assigner: [email protected] Source: [email protected]
NVD Status：Modified，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2021-20316 is rated Moderate Risk (44.9/100): CVSS Medium severity, with medium exploitation likelihood (EPSS 0.76%). 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-2021-20316

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 2026-06-23 0.74% 0.76% +0.02%
2 2026-06-15 1.10% 0.74% -0.36%
3 2026-06-14 — 1.10% —

Full EPSS history (25 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2021-20316

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
6.8 3.1 MEDIUM
CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/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: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:N)
Service keeps running; no real outage angle.
 1.6 5.2 [email protected]

Weakness enumeration for CVE-2021-20316

OS Trackers for CVE-2021-20316

vendor priority summary link
alpine medium CVE-2021-20316: 1 source package rows (samba); 95 state rows across 5 repos (3.19-main, 3.20-main, 3.21-main, 3.22-main, edge-main); fixed 0, open 95. https://security.alpinelinux.org/vuln/CVE-2021-20316
debian not yet assigned CVE-2021-20316 not yet assigned priority: Debian including 1 source packages (samba), 5 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): resolved 4, open 1. https://security-tracker.debian.org/tracker/CVE-2021-20316
gentoo high CVE-2021-20316: 1 GLSA(s) (202309-06), 1 atom(s) (net-fs/samba); latest impact high. https://bugs.gentoo.org/buglist.cgi?quicksearch=CVE-2021-20316
redhat medium — https://access.redhat.com/security/cve/CVE-2021-20316
suse medium CVE-2021-20316 severity moderate: SUSE including 602 source package names (0.21.0.3.2.10:krb5-1.19.2-150300.8.3.2, 1.1.2.3.2.10:krb5-1.19.2-150300.8.3.2, …), 2787 product×package rows across 152 product lines (Container bci/bci-init, Container bci/dotnet-aspnet, … (152 product lines)): Will Not Fix 1470, Fixed 1110, Known Affected 181, Known Not Affected 26. https://www.suse.com/security/cve/CVE-2021-20316/
ubuntu medium CVE-2021-20316 medium priority: Ubuntu including 1 source packages (samba), 15 status rows across 15 suites (bionic, focal, hirsute, impish, jammy, kinetic, lunar, mantic, noble, oracular, plucky, questing, trusty, upstream, xenial): ignored 6, not-affected 6, needed 2, released 1. https://ubuntu.com/security/CVE-2021-20316

Affected software / configurations for CVE-2021-20316

Vendor Product Version Raw CPE
samba samba < 4.15.0 cpe:2.3:a:samba:samba:*:*:*:*:*:*:*:*
debian debian_linux 10.0 cpe:2.3:o:debian:debian_linux:10.0:*:*:*:*:*:*:*
debian debian_linux 11.0 cpe:2.3:o:debian:debian_linux:11.0:*:*:*:*:*:*:*
redhat virtualization_host 4.0 cpe:2.3:a:redhat:virtualization_host:4.0:*:*:*:*:*:*:*
redhat enterprise_linux 8.0 cpe:2.3:o:redhat:enterprise_linux:8.0:*:*:*:*:*:*:*
redhat enterprise_linux_aus 8.6 cpe:2.3:o:redhat:enterprise_linux_aus:8.6:*:*:*:*:*:*:*
redhat enterprise_linux_eus 8.6 cpe:2.3:o:redhat:enterprise_linux_eus:8.6:*:*:*:*:*:*:*
redhat enterprise_linux_tus 8.6 cpe:2.3:o:redhat:enterprise_linux_tus:8.6:*:*:*:*:*:*:*

References for CVE-2021-20316

cvelogic Threat Intelligence