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GHSA-rc4r-wh2q-q6c4 CVE-2022-36109 GO-2022-0985

Docker supplementary group permissions not set up properly, allowing attackers to bypass primary group restrictions

Medium Go
Severity
5.3 / 10
Medium · CVSS 3.1
Exploit chance (EPSS)
1.04%
Chance of exploitation in the next 30 days. Higher than 64.08% of scored vulnerabilities.
Known exploited
No
Not in CISA's catalog
Weakness
CWE-863 Incorrect Authorization
Fix
20.10.18
Upgrade github.com/docker/docker to this version or later

Description

Moby is an open-source project created by Docker to enable software containerization. A bug was found in Moby (Docker Engine) where supplementary groups are not set up properly. If an attacker has direct access to a container and manipulates their supplementary group access, they may be able to use supplementary group access to bypass primary group restrictions in some cases, potentially gaining access to sensitive information or gaining the ability to execute code in that container. This bug is fixed in Moby (Docker Engine) 20.10.18. Users should update to this version when it is available. Running containers should be stopped and restarted for the permissions to be fixed. For users unable to upgrade, this problem can be worked around by not using the "USER $USERNAME" Dockerfile instruction. Instead by calling ENTRYPOINT ["su", "-", "user"] the supplementary groups will be set up properly.

Thanks to Steven Murdoch for reporting this issue.

Impact

If an attacker has direct access to a container and manipulates their supplementary group access, they may be able to use supplementary group access to bypass primary group restrictions in some cases, potentially gaining access to sensitive information or gaining the ability to execute code in that container.

Patches

This bug is fixed in Moby (Docker Engine) 20.10.18. Users should update to this version when it is available.

Workarounds

This problem can be worked around by not using the "USER $USERNAME" Dockerfile instruction. Instead by calling ENTRYPOINT ["su", "-", "user"] the supplementary groups will be set up properly.

References

https://www.benthamsgaze.org/2022/08/22/vulnerability-in-linux-containers-investigation-and-mitigation/

For more information

If you have any questions or comments about this advisory:

Affected versions

Go

PackageVulnerableFixed in
github.com/docker/docker
< 20.10.18
20.10.18
github.com/docker/docker
< 20.10.18+incompatible
20.10.18+incompatible

How to fix

Move to the fixed version or later with your package manager, update the lockfile, and run your tests. If the package only arrives through another dependency, upgrade that dependency first. If none of its releases pulls a fixed version yet, force the version with your package manager's override.

github.com/docker/docker Go → 20.10.18

go
go get github.com/docker/docker@v20.10.18 && go mod tidy

Severity breakdown

CVSS 3.1 5.3

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:L

Attack vector
Local
Attack complexity
Low
Privileges required
Low
User interaction
None
Scope
Unchanged
Confidentiality
Low
Integrity
Low
Availability
Low

Weakness

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 to prevent it
  • Architecture and Design: Divide the product into anonymous, normal, privileged, and administrative areas. Reduce the attack surface by carefully mapping roles with data and functionality. Use role-based access control (RBAC) [REF-229] to enforce the roles at the appropriate boundaries. Note that this approach may not protect against horizontal authorization, i.e., it will not protect a user from attacking others with the same role.
  • Architecture and Design: Ensure that access control checks are performed related to the business logic. These checks may be different than the access control checks that are applied to more generic resources such as files, connections, processes, memory, and database records. For example, a database may restrict access for medical records to a specific database user, but each record might only be intended to be accessible to the patient and the patient's doctor [REF-7].
  • Architecture and Design: Use a vetted library or framework that does not allow this weakness to occur or provides constructs that make this weakness easier to avoid. For example, consider using authorization frameworks such as the JAAS Authorization Framework [REF-233] and the OWASP ESAPI Access Control feature [REF-45].
  • Architecture and Design: For web applications, make sure that the access control mechanism is enforced correctly at the server side on every page. Users should not be able to access any unauthorized functionality or information by simply requesting direct access to that page. One way to do this is to ensure that all pages containing sensitive information are not cached, and that all such pages restrict access to requests that are accompanied by an active and authenticated session token associated with a user who has the required permissions to access that page.
  • System Configuration, Installation: Use the access control capabilities of your operating system and server environment and define your access control lists accordingly. Use a "default deny" policy when defining these ACLs.

References

Advisories

Packages

Other links

Timeline

  1. Published
  2. Last updated by the source
  3. Latest EPSS score
AdvisorySeverityWhy it's related
GHSA-hmfx-3pcx-653p
Supplementary groups are not set up properly in github.com/containerd/containerd
High Linked by the source
GHSA-fjm8-m7m6-2fjp
Buildah's incorrect handling of the supplementary groups may lead to data disclosure, modification
High Linked by the source
GHSA-rg2x-37c3-w2rh
Docker: Race condition in docker cp allows bind mount redirection to host path
High Also affects github.com/docker/docker
GHSA-vp62-88p7-qqf5
Docker: Race condition in docker cp allows creation of arbitrary empty files on the host via symlink swap
Medium Also affects github.com/docker/docker
GHSA-x86f-5xw2-fm2r
Docker: `PUT /containers/{id}/archive` executes container binary on the host
High Also affects github.com/docker/docker
GO-2026-4887
Moby has AuthZ plugin bypass when provided oversized request bodies
High Also affects github.com/docker/docker
GHSA-pxq6-2prw-chj9
Moby has an Off-by-one error in its plugin privilege validation
High Also affects github.com/docker/docker
GHSA-4vq8-7jfc-9cvp
Moby firewalld reload removes bridge network isolation
Medium Also affects github.com/docker/docker
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