Automation-controller: automation-controller: incomplete sanitize_jinja() regex allows jinja template injection into ad-hoc module_args, machine-credential fields, and host names, reaching ansible-core templating in the execution environment

A flaw was found in the automation-controller input-validation guard sanitize_jinja(). The function uses two regular expressions to reject user-supplied Jinja, but the patterns stop at the first interior '}' or '%' character, so a Jinja expression containing an inner brace (for example an empty dict) is accepted while remaining valid Jinja. Because sanitize_jinja() is the sole guard on several launch-time fields — ad-hoc command module_args, Machine-credential username / become_method / become_user, and inventory host names — a low-privileged user can inject Jinja that ansible-core evaluates in the execution environment. This enables execution of arbitrary commands in the execution environment (bypassing an administrator's AD_HOC_COMMANDS module allowlist) and disclosure of secrets belonging to credentials the attacker cannot read (by templating a co-attached credential's injected environment variables), across the credential access-control boundary.

The product implements a protection mechanism that relies on a list of inputs (or properties of inputs) that are not allowed by policy or otherwise require other action to neutralize before additional processing takes place, but the list is incomplete.

An attacker operating through a network path may attempt exploitation with low privileges. If successful, the issue may cause the confidentiality, integrity or availability impact described by the vendor.