CVE-2025-47917

HIGH

Mbed TLS < 3.6.4 - Use-After-Free in mbedtls_x509_string_to_names()

Title source: llm
STIX 2.1

Exploitation Summary

EIP tracks 2 public exploits for CVE-2025-47917. PoCs published by Byte Reaper, byteReaper77.

AI-analyzed exploit summary This exploit leverages a use-after-free vulnerability in Mbed TLS ≤ 3.6.4 to achieve remote code execution by manipulating heap memory and injecting shellcode. It includes ASLR checks and heap spraying techniques to ensure reliability.

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).

Exploits (2)

exploitdb WORKING POC
by Byte Reaper · clocalmultiple
https://www.exploit-db.com/exploits/52427

This exploit leverages a use-after-free vulnerability in Mbed TLS ≤ 3.6.4 to achieve remote code execution by manipulating heap memory and injecting shellcode. It includes ASLR checks and heap spraying techniques to ensure reliability.

Classification
Working Poc 95%
Attack Type
Rce
Complexity
Complex
Reliability
Reliable
Target: Mbed TLS ≤ 3.6.4
No auth needed
Prerequisites: ASLR disabled · root privileges to run the exploit
devstral-2 · analyzed Feb 16, 2026 Full analysis →
nomisec WORKING POC 1 stars
by byteReaper77 · poc
https://github.com/byteReaper77/CVE-2025-47917

This repository contains a functional exploit for CVE-2025-47917, a Use-After-Free (UAF) vulnerability in mbedTLS 3.6.4's name parsing function. The exploit leverages heap spraying and shellcode injection to achieve arbitrary code execution, demonstrated via a reverse shell.

Classification
Working Poc 95%
Attack Type
Rce
Complexity
Complex
Reliability
Reliable
Target: mbedTLS < 3.6.4
No auth needed
Prerequisites: Linux environment · mbedTLS < 3.6.4 installed · ASLR disabled · root privileges for setup
devstral-2 · analyzed Feb 18, 2026 Full analysis →

Scores

CVSS v3 8.9
EPSS 0.0843
EPSS Percentile 92.6%
Attack Vector NETWORK
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:L/I:H/A:H

CISA SSVC

Vulnrichment
Exploitation none
Automatable no
Technical Impact total

Details

CWE
CWE-416
Status published
Products (1)
arm/mbed_tls < 3.6.4
Published Jul 20, 2025
Tracked Since Feb 18, 2026