CVE-2025-47917
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).
- Affected
- Mbed · mbedtls
- CVSS v3.1 NVD
- 9.8 CRITICAL
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H - CVSS v3.1 MITRE
- 8.9 HIGH
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:L/I:H/A:H - EPSS
- 2.27% chance of exploitation in the next 30 days, 83rd percentile
- Published
- 2025-07-20
- Updated
- 2025-11-03
Proof-of-concept exploits (1)
- byteReaper77/CVE-2025-479171★ · 2025-07-22
ExploitDB entries (1)
Security advisories
- https://mbed-tls.readthedocs.io/en/latest/tech-updates/security-advisories
- Mbed-TLS/mbedtls-docs/blob/main/security-advisories/mbedtls-security-advisory-2025-06-7.md