Double Free in Op-Tee Optee OS
CVE-2023-41325
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.
Vulnerability class: Double Free
Published · last modified .
CVSS v3 metric
CVSS v3 base score 7.4 (High). Vector: CVSS:3.1/AV:L/AC:L/PR:H/UI:R/S:C/C:H/I:H/A:N.
EPSS exploit prediction
EPSS: 0.004 (31.4th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 31st percentile — 31.4% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.004 · newest: 0.004 · change: 0.000
Affected products
- Op-Tee Optee OS — versions >= 3.20, < 3.22
- Trustedfirmware Op-Tee — versions 3.22.0
Weakness classification (CWE)
References
- github.com/OP-TEE/optee_os/security/advisories/GHSA-jrw7-63cq-7vhm (Exploit, Vendor Advisory)
- github.com/OP-TEE/optee_os/commit/e2ec831cb07ed0099535c7c140cb6338aa62816a (Patch)
Frequently asked questions
- What is CVE-2023-41325?
- CVE-2023-41325 is a high-severity vulnerability in Op-Tee Optee OS, classified under Double Free. CVSS score: 7.4/10. Published 2023-09-15.
- How severe is CVE-2023-41325?
- High severity. CVSS v3 base score is 7.4 out of 10.