CVE-2020-8908: Temp directory permission issue in Guava

A temp directory creation vulnerability exist in Guava versions prior to 30.0 allowing an attacker with access to the machine to potentially access data in a temporary directory created by the Guava com.google.common.io.Files.createTempDir(). The permissions granted to the directory created default to the standard unix-like /tmp ones, leaving the files open. We recommend updating Guava to version 30.0 or later, or update to Java 7 or later, or to explicitly change the permissions after the creation of the directory if neither are possible.

Reference: https://github.com/google/guava/issues/4011

Upstream patch: https://github.com/google/guava/commit/fec0dbc4634006a6162cfd4d0d09c962073ddf40

— Red Hat

A temp directory creation vulnerability exists in all versions of Guava, allowing an attacker with access to the machine to potentially access data in a temporary directory created by the Guava API com.google.common.io.Files.createTempDir(). By default, on unix-like systems, the created directory is world-readable (readable by an attacker with access to the system). The method in question has been marked @Deprecated in versions 30.0 and later and should not be used. For Android developers, we recommend choosing a temporary directory API provided by Android, such as context.getCacheDir(). For other Java developers, we recommend migrating to the Java 7 API java.nio.file.Files.createTempDirectory() which explicitly configures permissions of 700, or configuring the Java runtime's java.io.tmpdir system property to point to a location whose permissions are appropriately configured.

A temp directory creation vulnerability exists in Guava prior to version 32.0.0 allowing an attacker with access to the machine to potentially access data in a temporary directory created by the Guava com.google.common.io.Files.createTempDir(). The permissions granted to the directory created default to the standard unix-like /tmp ones, leaving the files open. Maintainers recommend explicitly changing the permissions after the creation of the directory, or removing uses of the vulnerable method.