Impala sessions use a 16 byte secret to verify that the session is not being hijacked by another user. However, these secrets appear in the Impala logs, therefore Impala users with access to the logs can use another authenticated user's sessions with specially constructed requests. This means the attacker is able to execute statements for which they don't have the necessary privileges otherwise. Impala deployments with Apache Sentry or Apache Ranger authorization enabled may be vulnerable to privilege escalation if an authenticated attacker is able to hijack a session or query from another authenticated user with privileges not assigned to the attacker. Impala deployments with audit logging enabled may be vulnerable to incorrect audit logging as a user could undertake actions that were logged under the name of a different authenticated user. Constructing an attack requires a high degree of technical sophistication and access to the Impala system as an authenticated user. Mitigation: If an Impala deployment uses Apache Sentry, Apache Ranger or audit logging, then users should upgrade to a version of Impala with the fix for IMPALA-10600. The Impala 4.0 release includes this fix. This hides session secrets from the logs to eliminate the risk of any attack using this mechanism. In lieu of an upgrade, restricting access to logs that expose secrets will reduce the risk of an attack. Restricting access to the Impala deployment to trusted users will also reduce the risk of an attack. Log redaction techniques can be used to redact secrets from the logs.

In Apache Impala 2.7.0 to 3.2.0, an authenticated user with access to the IDs of active Impala queries or sessions can interact with those sessions or queries via a specially-constructed request and thereby potentially bypass authorization and audit mechanisms. Session and query IDs are unique and random, but have not been documented or consistently treated as sensitive secrets. Therefore they may be exposed in logs or interfaces. They were also not generated with a cryptographically secure random number generator, so are vulnerable to random number generator attacks that predict future IDs based on past IDs. Impala deployments with Apache Sentry or Apache Ranger authorization enabled may be vulnerable to privilege escalation if an authenticated attacker is able to hijack a session or query from another authenticated user with privileges not assigned to the attacker. Impala deployments with audit logging enabled may be vulnerable to incorrect audit logging as a user could undertake actions that were logged under the name of a different authenticated user. Constructing an attack requires a high degree of technical sophistication and access to the Impala system as an authenticated user.

In Apache Impala before 3.0.1, ALTER TABLE/VIEW RENAME required ALTER on the old table. This may pose a potential security risk, such as having ALTER on a table and ALL on a particular database allows a user to move the table to a database with ALL, which will automatically grant that user with ALL privilege on that table due to the privilege inherited from the database.

Missing authorization check in Apache Impala before 3.0.1 allows a Kerberos-authenticated but unauthorized user to inject random data into a running query, leading to wrong results for a query.

In Apache Impala (incubating) before 2.10.0, a malicious user with "ALTER" permissions on an Impala table can access any other Kudu table data by altering the table properties to make it "external" and then changing the underlying table mapping to point to other Kudu tables. This violates and works around the authorization requirement that creating a Kudu external table via Impala requires an "ALL" privilege at the server scope. This privilege requirement for "CREATE" commands is enforced to precisely avoid this scenario where a malicious user can change the underlying Kudu table mapping. The fix is to enforce the same privilege requirement for "ALTER" commands that would make existing non-external Kudu tables external.