Description

Dokku is a docker-powered platform as a service. In Dokku versions before 0.38.25, a user with app-level Dokku access and remote SSH access to execute docker-options commands can store arbitrary strings through the docker-options plugin, and those strings are later concatenated into DOCKER_ARGS and processed by Bash eval during build, deploy, or run operations. Shell command substitutions in the stored values are interpreted on the host, allowing arbitrary command execution with the privileges of the dokku operating-system user. This issue is fixed in version 0.38.25.

Executive Summary

Technical Details

Mitigations

References

Additional Metadata

{
  "score": "9.0",
  "pubDate": "2026-10-14T16:17:54.470Z",
  "pubdate": "2026-10-14T16:17:54.470Z",
  "executiveSummary": "A critical command injection vulnerability exists within the Dokku platform, specifically impacting versions prior to 0.38.25. The flaw originates from the improper handling of user-supplied input within the docker-options plugin, which facilitates the persistence of arbitrary strings for Docker container configuration.\nThe vulnerability allows an authenticated user with app-level access and remote SSH capabilities to inject malicious shell commands. Because these inputs are insecurely passed to a Bash eval execution context during deployment or runtime operations, the injected commands are executed directly on the host system.\nThe resulting impact is total system compromise, granting the attacker the privileges associated with the dokku operating-system user. This represents a significant security risk, as it permits unauthorized administrative actions, data exfiltration, or lateral movement within the infrastructure. Exploitation is contingent upon having app-level Dokku access, which must be strictly managed to mitigate this threat.",
  "technicalDetails": "The root cause of this vulnerability lies in the insecure concatenation of configuration strings within the Dokku docker-options plugin. The system accepts user-defined Docker arguments and stores them persistently. During subsequent build, deploy, or run lifecycle events, these stored strings are incorporated into the DOCKER_ARGS variable without sufficient sanitization or neutralization of shell metacharacters.\nThe attack flow begins when an attacker, already possessing app-level access and SSH connectivity to the Dokku host, utilizes the docker-options command to inject a malicious payload. By crafting an argument that includes Bash command substitution syntax (such as $(command) or `command`), the attacker embeds arbitrary code into the plugin's configuration store.\nWhen the Dokku agent triggers an operation—such as deploying a new build or restarting a container—the DOCKER_ARGS variable is parsed and processed. The system invokes a Bash eval statement to evaluate these parameters. Because the malicious input is interpreted directly by the shell, the command substitution is expanded on the host machine. This effectively bypasses intended container isolation, allowing the shell to execute the attacker's payload.\nThe execution occurs with the privileges of the dokku operating-system user. This user typically holds significant authority over the platform's lifecycle scripts and deployment directories. Consequently, an attacker can achieve persistent unauthorized access, modify system configurations, or interact with other hosted applications. The vulnerability affects all versions of Dokku prior to 0.38.25. The lack of input validation on the docker-options plugin acts as the primary failure point, enabling command injection via a standard management interface that lacks necessary command parameterization or strict allow-listing of input strings."
}