OP-TEE Trusted OS is the secure side implementation of OP-TEE project, a Trusted Execution Environment. Versions prior to 3.19.0, contain an Improper Validation of Array Index vulnerability. The function `cleanup_shm_refs()` is called by both `entry_invoke_command()` and `entry_open_session()`. The commands `OPTEE_MSG_CMD_OPEN_SESSION` and `OPTEE_MSG_CMD_INVOKE_COMMAND` can be executed from the normal world via an OP-TEE SMC. This function is not validating the `num_params` argument, which is only limited to `OPTEE_MSG_MAX_NUM_PARAMS` (127) in the function `get_cmd_buffer()`. Therefore, an attacker in the normal world can craft an SMC call that will cause out-of-bounds reading in `cleanup_shm_refs` and potentially freeing of fake-objects in the function `mobj_put()`. A normal-world attacker with permission to execute SMC instructions may exploit this flaw. Maintainers believe this problem permits local privilege escalation from the normal world to the secure world. Version 3.19.0 contains a fix for this issue. There are no known workarounds.
Metrics
CVSS Version: 3.1 |
Base Score: 8.2 HIGH Vector: CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:H
l➤ Exploitability Metrics: Attack Vector (AV)* LOCAL Attack Complexity (AC)* LOW Privileges Required (PR)* HIGH User Interaction (UI)* NONE Scope (S)* CHANGED
l➤ Impact Metrics: Confidentiality Impact (C)* HIGH Integrity Impact (I)* HIGH Availability Impact (A)* HIGH
Weakness Enumeration (CWE)
CWE-ID: CWE-129 CWE Name: CWE-129: Improper Validation of Array Index Source: OP-TEE
Common Attack Pattern Enumeration and Classification (CAPEC)