KubeEdge: ConfigUpdateJob updateFields enables remote shell injection and code execution on edge nodes

Description

KubeEdge ConfigUpdateJob processing was vulnerable to command injection on edge nodes.

The updateFields values from a ConfigUpdateJob were concatenated into a command string and executed through a system shell. An authenticated user with sufficient permissions to create or update ConfigUpdateJob resources could include shell metacharacters in the supplied configuration fields and cause unintended commands to be executed on targeted edge nodes.

Impact

Successful exploitation could allow an authenticated attacker to execute arbitrary commands on affected edge nodes with the privileges of the KubeEdge process handling the ConfigUpdateJob.

The attacker must already have permission to create or modify ConfigUpdateJob resources and target an enrolled edge node.

Patches

The fix removes shell-based command construction and invokes keadm config-update using structured command arguments.

The complete --set value is passed as a single literal argument, preventing shell metacharacters from being interpreted as commands.

Fixes are planned for the following maintained releases:

• v1.23.1
• v1.22.2
• v1.21.2

Workarounds

Until a patched release is available:

• restrict RBAC permissions for creating or modifying ConfigUpdateJob resources;
• allow only trusted administrators to submit configuration update jobs;
• avoid using ConfigUpdateJob in environments where its input cannot be fully trusted;
• monitor ConfigUpdateJob resources and edge-node process activity for unexpected commands or changes.

Credits

KubeEdge thanks Sang-Hoon Choi (KoreaSecurity, Sejong University)
for responsibly reporting this issue and for coordinating with the KubeEdge
maintainers through the security disclosure process.