CVE-2023-41325: op-tee optee_os Double Free

Vulnerability summary

CVE-2023-41325 is a high (CVSS 7.4) Double Free vulnerability in op-tee optee_os. EPSS estimates a 0.39% chance of exploitation in the next 30 days, higher than 31.5% of scored vulnerabilities. 1 public exploit is recorded.

Timeline

1. 15-09-2023
   PublishedVulnerability first disclosed.
2. 25-09-2024
   Last modifiedVulnerability information updated.

Description

OP-TEE is a Trusted Execution Environment (TEE) designed as companion to a non-secure Linux kernel running on Arm; Cortex-A cores using the TrustZone technology. Starting in version 3.20 and prior to version 3.22, `shdr_verify_signature` can make a double free. `shdr_verify_signature` used to verify a TA binary before it is loaded. To verify a signature of it, allocate a memory for RSA key. RSA key allocate function (`sw_crypto_acipher_alloc_rsa_public_key`) will try to allocate a memory (which is optee’s heap memory). RSA key is consist of exponent and modulus (represent as variable `e`, `n`) and it allocation is not atomic way, so it may succeed in `e` but fail in `n`. In this case sw_crypto_acipher_alloc_rsa_public_key` will free on `e` and return as it is failed but variable ‘e’ is remained as already freed memory address . `shdr_verify_signature` will free again that memory (which is `e`) even it is freed when it failed allocate RSA key. A patch is available in version 3.22. No known workarounds are available.

• CWE-415Double FreeThe product calls free() twice on the same memory address.