CVE-2021-41103

Description

containerd is an open source container runtime with an emphasis on simplicity, robustness and portability. A bug was found in containerd where container root directories and some plugins had insufficiently restricted permissions, allowing otherwise unprivileged Linux users to traverse directory contents and execute programs. When containers included executable programs with extended permission bits (such as setuid), unprivileged Linux users could discover and execute those programs. When the UID of an unprivileged Linux user on the host collided with the file owner or group inside a container, the unprivileged Linux user on the host could discover, read, and modify those files. This vulnerability has been fixed in containerd 1.4.11 and containerd 1.5.7. Users should update to these version when they are released and may restart containers or update directory permissions to mitigate the vulnerability. Users unable to update should limit access to the host to trusted users. Update directory permission on container bundles directories.

CvssV3 impact

BaseSeverity

HIGH

ConfidentialityImpact

HIGH

AttackComplexity

LOW

Scope

UNCHANGED

AttackVector

LOCAL

AvailabilityImpact

HIGH

IntegrityImpact

HIGH

PrivilegesRequired

LOW

BaseScore

7.8

VectorString

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

Version

3.1

UserInteraction

NONE

CvssV2 impact

AccessComplexity

LOW

ConfidentialityImpact

COMPLETE

AvailabilityImpact

COMPLETE

IntegrityImpact

COMPLETE

BaseScore

7.2

VectorString

AV:L/AC:L/Au:N/C:C/I:C/A:C

Version

2.0

AccessVector

LOCAL

Authentication

NONE