CVE-2024-2905
Description
A security vulnerability has been discovered within rpm-ostree, pertaining to the /etc/shadow file in default builds having the world-readable bit enabled. This issue arises from the default permissions being set at a higher level than recommended, potentially exposing sensitive authentication data to unauthorized access.
Statement
This vulnerability lets local, unconfined applications read the hashed password for all users of the system from those files. To gain further access to the system, those hashed passwords need to be brute-forced to discover the real passwords that may be used to authenticate as a more privileged user on the system, for example over SSH.
On systems with SELinux enabled and in enforcing mode, access to those files is limited to unconfined (usually interactive) users, unconfined systemd services and privileged containers. Confined daemons, users and containers are not able to access them.
Only OpenShift clusters installed on OCP version 4.14 and later are affected. OpenShift Clusters installed on previous OCP releases or updated to 4.14 and later are not affected, because /etc/shadow is usually “locally modified” and the local version remains. Clusters with no passwords set for any users (i.e. only SSH keys were used; the OpenShift default) are not impacted by this vulnerability even though it is present on the node.
Mitigation
If you need to apply the fix immediately, you can run the following commands, using credentials that have administrator access to an OpenShift cluster:
# List current permissions for all nodes
for node in $( oc get nodes -oname) ; do echo $node ; oc debug $node -- bash -c "ls -alhZ /host/etc/*shadow*"; done
# Set correct permissions
for node in $( oc get nodes -oname) ; do echo $node ; oc debug $node -- chmod --verbose 0000 /host/etc/shadow /host/etc/gshadow /host/etc/shadow- /host/etc/gshadow-; done
As a precaution, we recommend rotating all user credentials stored in those files.
Common Vulnerability Scoring System (CVSS) Score Details
Info alert:Important note
CVSS scores for open source components depend on vendor-specific factors (e.g. version or build chain). Therefore, Red Hat's score and impact rating can be different from NVD and other vendors. Red Hat remains the authoritative CVE Naming Authority (CNA) source for its products and services (see Red Hat classifications).
CVSS v3 Score Breakdown
| Red Hat | NVD | cve.org | |
|---|---|---|---|
| Base Score | 6.2 | N/A | 6.2 |
| Attack Vector | Local | N/A | Local |
| Attack Complexity | Low | N/A | Low |
| Privileges Required | None | N/A | None |
| User Interaction | None | N/A | None |
| Scope | Unchanged | N/A | Unchanged |
| Confidentiality | High | N/A | High |
| Integrity Impact | None | N/A | None |
| Availability Impact | None | N/A | None |
Vector
Red Hat: CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
cve.org: CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
Understanding the Weakness (CWE)
Confidentiality
Technical Impact: Read Application Data; Read Files or Directories
An attacker may be able to read sensitive information from the associated resource, such as credentials or configuration information stored in a file.
Access Control
Technical Impact: Gain Privileges or Assume Identity
An attacker may be able to modify critical properties of the associated resource to gain privileges, such as replacing a world-writable executable with a Trojan horse.
Integrity,Other
Technical Impact: Modify Application Data; Other
An attacker may be able to destroy or corrupt critical data in the associated resource, such as deletion of records from a database.
Frequently Asked Questions
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