CVE-2021-20188: Github.com/containers/libpod Improper Authorization Vulnerability

HIGH
Advisory Identifier: GHSA-9h63-7qf6-mv6r
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CVSS 7.0
CWE-863
Published
Advisory Summary

CVE-2021-20188 is a HIGH (CVSS 7.0) improper authorization vulnerability (CWE-863: Incorrect Authorization) affecting Github.com/containers/libpod libraries in the Go ecosystem. The issue involves improper authorization in github.com/containers/libpod. Remediation is available by upgrading affected packages to version 1.7.0.

CVE-2021-20188 at a Glance

CVE Identifier CVE-2021-20188
GHSA Identifier GHSA-9h63-7qf6-mv6r
Severity HIGH
CVSS v3.1 Base Score 7.0
CWE Classification CWE-863: Incorrect Authorization
Affected Product Github.com/containers/libpod
Package Ecosystem Go
Published Date
Last Updated

Security Impact

CVSS: 7.0

The security impact metrics below are parsed directly from the CVSS v3.1 vector string (CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H).

Attack Vector Local (AV:L)
Attack Complexity High (AC:H)
Privileges Required Low (PR:L)
User Interaction None (UI:N)
Scope Unchanged (S:U)
Confidentiality High (C:H)
Integrity High (I:H)
Availability High (A:H)

How to Fix CVE-2021-20188

To remediate this vulnerability, upgrade all affected Github.com/containers/libpod dependencies to a patched release. Both direct and transitive dependencies should be checked, as frameworks or security libraries may pull in vulnerable versions transitively.

github.com/containers/libpod fixed: 1.7.0 
Upgrade github.com/containers/libpod to 1.7.0
Verify Direct and Transitive Dependencies

Run the following command in your project directory to verify that all resolved dependencies use the patched release: 

inspect dependencies for github.com/containers/libpod

How to Check if You Are Affected

To determine whether your application is affected by CVE-2021-20188, inspect your project dependencies for Github.com/containers/libpod:

inspect dependencies for github.com/containers/libpod

Analyze the terminal output to locate any version of Github.com/containers/libpod in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than 1.7.0), your application is affected.

Note: Verify declared build manifests and deployed runtime container environments.

Technical Details

Vulnerability Mechanism & Technical Analysis

This vulnerability is classified under CWE-863: Incorrect Authorization, where the product performs an authorization check when an actor attempts to access a resource or perform an action, but it does not correctly perform the check. In Github.com/containers/libpod, software state validation or input boundaries are circumvented during processing. Review the official source advisory statement below for specific affected components, classes, and reproduction details.

Source Advisory Statement

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.

CVE-2021-20188 Affected Github.com/containers/libpod Versions

1 component(s)
Fixed Versions:
1.7.0
Product / Package Ecosystem Affected Versions Fixed Version
github.com/containers/libpod
golang/github.com/containers/libpod
Go
< 1.7.0
1.7.0

References

NVD — CVE-2021-20188 NVD
https://nvd.nist.gov/vuln/detail/CVE-2021-20188
Security Fix Commit FIX COMMIT
https://github.com/containers/podman/commit/2c7b579fe7328dc6db48bdaf60d0ddd9136b1e24
Security Fix Commit FIX COMMIT
https://github.com/containers/podman/commit/c8bd4746151e6ae37d49c4688f2f64e03db429fc
Security Fix Commit FIX COMMIT
https://github.com/containers/podman/commit/dcf3c742b1ac4d641d66810113f3d17441a412f4
bugzilla.redhat.com/show_bug.cgi WEB
https://bugzilla.redhat.com/show_bug.cgi?id=1915734

Frequently Asked Questions

What is CVE-2021-20188?
CVE-2021-20188 is a security vulnerability in Github.com/containers/libpod involving Improper Authorization in github.com/containers/libpod under CWE-863: Incorrect Authorization.
Which Github.com/containers/libpod versions are affected?
Affected versions include releases prior to 1.7.0 across affected packages: github.com/containers/libpod.
What version fixes CVE-2021-20188?
Upgrading to 1.7.0 (or the latest patched release for your respective branch) resolves the vulnerability.
Is github.com/containers/libpod affected?
Yes, github.com/containers/libpod is affected in releases prior to 1.7.0. Upgrade your dependency to 1.7.0 or later.
What is the CVSS score of CVE-2021-20188?
CVE-2021-20188 has a CVSS v3.1 base score of 7.0 (HIGH) with vector string CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H.
What CWE is associated with CVE-2021-20188?
CVE-2021-20188 is classified under CWE-863: Incorrect Authorization (The product performs an authorization check when an actor attempts to access a resource or perform an action, but it does not correctly perform the check.).
How can I check Go dependencies for CVE-2021-20188?
Run the dependency tree command: 'inspect dependencies for github.com/containers/libpod'. This command lists direct and transitive dependencies in your build configuration so you can verify if a vulnerable version is resolved.
Machine-readable OSV JSON OSV v1.5 Schema
Normalized schema output
View Raw JSON 
{
  "schema_version" : "1.4.0",
  "id" : "GHSA-9h63-7qf6-mv6r",
  "modified" : "2021-05-07T22:01:02Z",
  "published" : "2021-05-18T18:33:12Z",
  "aliases" : [ "CVE-2021-20188" ],
  "summary" : "Improper Authorization in github.com/containers/libpod",
  "details" : "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.",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "Go",
      "name" : "github.com/containers/libpod"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "fixed" : "1.7.0"
      } ]
    } ]
  } ],
  "references" : [ {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2021-20188"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/containers/podman/commit/2c7b579fe7328dc6db48bdaf60d0ddd9136b1e24"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/containers/podman/commit/c8bd4746151e6ae37d49c4688f2f64e03db429fc"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/containers/podman/commit/dcf3c742b1ac4d641d66810113f3d17441a412f4"
  }, {
    "type" : "WEB",
    "url" : "https://bugzilla.redhat.com/show_bug.cgi?id=1915734"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-863" ],
    "severity" : "HIGH",
    "github_reviewed" : true,
    "github_reviewed_at" : "2021-05-07T22:01:02Z",
    "nvd_published_at" : null
  }
}