Gradle vulnerabilities

gradle-completion provides Bash and Zsh completion support for Gradle. A command injection vulnerability was found in gradle-completion up to and including 9.3.0 that allows arbitrary code execution when a user triggers Bash tab completion in a project containing a malicious Gradle build file. The `gradle-completion` script for Bash fails to adequately sanitize Gradle task names and task descriptions, allowing command injection via a malicious Gradle build file when the user completes a command in Bash (without them explicitly running any task in the build). For example, given a task description that includes a string between backticks, then that string would be evaluated as a command when presenting the task description in the completion list. While task execution is the core feature of Gradle, this inherent execution may lead to unexpected outcomes. The vulnerability does not affect zsh completion. The first patched version is 9.3.1. As a workaround, it is possible and effective to temporarily disable bash completion for Gradle by removing `gradle-completion` from `.bashrc` or `.bash_profile`.

Gradle is a build automation tool, and its native-platform tool provides Java bindings for native APIs. When resolving dependencies in versions before 9.3.0, some exceptions were not treated as fatal errors and would not cause a repository to be disabled. If a build encountered one of these exceptions, Gradle would continue to the next repository in the list and potentially resolve dependencies from a different repository. An exception like NoHttpResponseException can indicate transient errors. If the errors persist after a maximum number of retries, Gradle would continue to the next repository. This behavior could allow an attacker to disrupt the service of a repository and leverage another repository to serve malicious artifacts. This attack requires the attacker to have control over a repository after the disrupted repository. Gradle has introduced a change in behavior in Gradle 9.3.0 to stop searching other repositories when encountering these errors.

Gradle is a build automation tool, and its native-platform tool provides Java bindings for native APIs. When resolving dependencies in versions before 9.3.0, some exceptions were not treated as fatal errors and would not cause a repository to be disabled. If a build encountered one of these exceptions, Gradle would continue to the next repository in the list and potentially resolve dependencies from a different repository. If a Gradle build used an unresolvable host name, Gradle would continue to work as long as all dependencies could be resolved from another repository. An unresolvable host name could be caused by allowing a repository's domain name registration to lapse or typo-ing the real domain name. This behavior could allow an attacker to register a service under the host name used by the build and serve malicious artifacts. The attack requires the repository to be listed before others in the build configuration. Gradle has introduced a change in behavior in Gradle 9.3.0 to stop searching other repositories when encountering these errors.

Gradle is a build tool with a focus on build automation. In versions prior to 7.2, start scripts generated by the `application` plugin and the `gradlew` script are both vulnerable to arbitrary code execution when an attacker is able to change environment variables for the user running the script. This may impact those who use `gradlew` on Unix-like systems or use the scripts generated by Gradle in thieir application on Unix-like systems. For this vulnerability to be exploitable, an attacker needs to be able to set the value of particular environment variables and have those environment variables be seen by the vulnerable scripts. This issue has been patched in Gradle 7.2 by removing the use of `eval` and requiring the use of the `bash` shell. There are a few workarounds available. For CI/CD systems using the Gradle build tool, one may ensure that untrusted users are unable to change environment variables for the user that executes `gradlew`. If one is unable to upgrade to Gradle 7.2, one may generate a new `gradlew` script with Gradle 7.2 and use it for older versions of Gradle. Fpplications using start scripts generated by Gradle, one may ensure that untrusted users are unable to change environment variables for the user that executes the start script. A vulnerable start script could be manually patched to remove the use of `eval` or the use of environment variables that affect the application's command-line. If the application is simple enough, one may be able to avoid the use of the start scripts by running the application directly with Java command.

In Gradle before version 7.0, on Unix-like systems, the system temporary directory can be created with open permissions that allow multiple users to create and delete files within it. Gradle builds could be vulnerable to a local privilege escalation from an attacker quickly deleting and recreating files in the system temporary directory. This vulnerability impacted builds using precompiled script plugins written in Kotlin DSL and tests for Gradle plugins written using ProjectBuilder or TestKit. If you are on Windows or modern versions of macOS, you are not vulnerable. If you are on a Unix-like operating system with the "sticky" bit set on your system temporary directory, you are not vulnerable. The problem has been patched and released with Gradle 7.0. As a workaround, on Unix-like operating systems, ensure that the "sticky" bit is set. This only allows the original user (or root) to delete a file. If you are unable to change the permissions of the system temporary directory, you can move the Java temporary directory by setting the System Property `java.io.tmpdir`. The new path needs to limit permissions to the build user only. For additional details refer to the referenced GitHub Security Advisory.

As mitigation for CVE-2020-1945 Apache Ant 1.10.8 changed the permissions of temporary files it created so that only the current user was allowed to access them. Unfortunately the fixcrlf task deleted the temporary file and created a new one without said protection, effectively nullifying the effort. This would still allow an attacker to inject modified source files into the build process.