CVE-2021-20188

A flaw was found in podman before 1.7.0. File permissions for non-root users running in a privileged container are not correctly checked. This flaw can be abused by a low-privileged user inside the container to access any other file in the container, even if owned by the root user inside the container. It does not allow to directly escape the container, though being a privileged container means that a lot of security features are disabled when running the container. The highest threat from this vulnerability is to data confidentiality and integrity as well as system availability.

Published: 2021-02-11 Last update: 2024-11-21 Assigner: [email protected] Source: [email protected]

Conclusion & alert: CVE-2021-20188 is rated Low Risk (36.9/100): CVSS High severity, with low exploitation likelihood (EPSS 0.08%). Mandatory action: 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-2021-20188

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 0.03% 0.08% +0.06%
2 2025-11-18 0.08% 0.03% -0.06%
3 2025-03-30 0.08%

Full EPSS history (10 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2021-20188

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
7.0 3.1 HIGH
CVSS:3.1/AV:L/AC:H/PR:L/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: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:H)
Could take the service down hard or make it unusable for people who depend on it.
1.0 5.9 [email protected]
6.9 2.0 MEDIUM
AV:L/AC:M/Au:N/C:C/I:C/A:C Click to expand
Access vector (AV:L)
Requires local access to the target system.
Access complexity (AC:M)
Exploitation needs some favorable conditions, but not exceptional ones.
Authentication (AU:N)
No authentication is required.
Confidentiality impact (C:C)
Complete confidentiality impact.
Integrity impact (I:C)
Complete integrity impact.
Availability impact (A:C)
Complete availability impact.
3.4 10.0 [email protected]

Weakness enumeration for CVE-2021-20188

GitHub Security Advisory for CVE-2021-20188

GHSA-9h63-7qf6-mv6r · Severity: high · Ecosystem: go — Improper Authorization in github.com/containers/libpod

OS Trackers for CVE-2021-20188

vendor priority summary link
debian not yet assigned CVE-2021-20188 not yet assigned priority: Debian including 1 source packages (libpod), 2 status rows across 2 suites (bookworm, bullseye): resolved 2. https://security-tracker.debian.org/tracker/CVE-2021-20188
redhat high https://access.redhat.com/security/cve/CVE-2021-20188
suse high CVE-2021-20188 severity important: SUSE including 28 source package names (buildah-1.14.9-1.module+el8.2.1+6689+748e6520, buildah-tests-1.14.9-1.module+el8.2.1+6689+748e6520, …), 43 product×package rows across 12 product lines (SUSE CaaS Platform 4.0, SUSE Enterprise Storage 6, … (12 product lines)): Fixed 26, Known Not Affected 17. https://www.suse.com/security/cve/CVE-2021-20188/
ubuntu medium CVE-2021-20188 medium priority: Ubuntu including 1 source packages (libpod), 16 status rows across 16 suites (bionic, focal, groovy, hirsute, impish, jammy, kinetic, lunar, mantic, noble, oracular, plucky, questing, trusty, upstream, xenial): ignored 7, DNE 6, needs-triage 3. https://ubuntu.com/security/CVE-2021-20188

Affected software / configurations for CVE-2021-20188

Vendor Product Version Raw CPE
podman_project podman < 1.7.0 cpe:2.3:a:podman_project:podman:*:*:*:*:*:*:*:*
redhat openshift_container_platform 3.11 cpe:2.3:a:redhat:openshift_container_platform:3.11:*:*:*:*:*:*:*
redhat enterprise_linux 7.0 cpe:2.3:o:redhat:enterprise_linux:7.0:*:*:*:*:*:*:*
redhat enterprise_linux 8.0 cpe:2.3:o:redhat:enterprise_linux:8.0:*:*:*:*:*:*:*

References for CVE-2021-20188

URL Tags
https://bugzilla.redhat.com/show_bug.cgi?id=1915734 Issue Tracking Patch Vendor Advisory
cvelogic Threat Intelligence