Vela Insecure Defaults

Vulnerability

Details

CVE-2022-39395 describes multiple insecure default configurations in Vela Server, Worker, and UI prior to versions 0.16.0 and 0.17.0 [1]. The defaults include allowing privileged Docker images to run without explicit administrator intent, permitting any GitHub user to enable repositories on a publicly accessible instance, and enabling pull request events by default [3][4]. These settings collectively create a significant attack surface for container breakouts and unauthorized code execution.

Exploitation

An attacker with a GitHub account can enable a malicious repository on a publicly accessible Vela instance and trigger a build that runs a privileged container [3]. Because the default configuration allows the target/vela-docker plugin to run as privileged, the attacker can break out of the container and gain access to the worker host operating system [3][4]. Additionally, if pull request events are enabled, any user who can create a pull request against an enabled repository can trigger a Vela job, potentially accessing secrets configured for pull request builds [4].

Impact

Successful exploitation leads to container breakout, granting the attacker full control over the worker host. This can result in compromise of the entire CI/CD infrastructure, exposure of secrets, and lateral movement within the environment [3][4]. The risk is elevated for publicly accessible Vela instances not protected by a VPN.

Mitigation

Users should upgrade to Vela Server 0.16.0, Worker 0.16.0, and UI 0.17.0 [1]. After upgrading, administrators must explicitly change default settings to secure the instance. Workarounds include setting VELA_RUNTIME_PRIVILEGED_IMAGES to empty, using VELA_REPO_ALLOWLIST to restrict repository access, and auditing enabled repositories to disable pull request events if not needed [1][3][4].