CVE-2025-47917 Information

Description

Mbed TLS before 3.6.4 allows a use-after-free in certain situations of applications that are developed in accordance with the documentation. The function mbedtls_x509_string_to_names() takes a head argument that is documented as an output argument. The documentation does not suggest that the function will free that pointer; however the function does call mbedtls_asn1_free_named_data_list() on that argument which performs a deep free(). As a result application code that uses this function (relying only on documented behavior) is likely to still hold pointers to the memory blocks that were freed resulting in a high risk of use-after-free or double-free. In particular the two sample programs x509/cert_write and x509/cert_req are affected (use-after-free if the san string contains more than one DN).

Reference

https://github.com/Mbed-TLS/mbedtls-docs/blob/main/security-advisories/mbedtls-security-advisory-2025-06-7.md https://mbed-tls.readthedocs.io/en/latest/tech-updates/security-advisories/

Related CNNVD

CNNVD-202507-2583 (Published: 2025-07-20)