#VU112445 Race condition in mbed TLS - CVE-2025-52496

Vulnerability identifier: #VU112445

Vulnerability risk: Medium

CVSSv4.0: 1.7 [CVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:N/VC:L/VI:L/VA:N/SC:L/SI:N/SA:N/E:U/U:Green]

CVE-ID: CVE-2025-52496

CWE-ID: CWE-362

Exploitation vector: Network

Exploit availability: No

Vulnerable software:
mbed TLS
Universal components / Libraries / Libraries used by multiple products

Vendor: ARM

Description

The vulnerability allows a remote attacker to perform MitM attack.

The vulnerability exists due to a race condition on x86 and amd64 systems that have the AESNI instruction, as it can be used for AES encryption and decryption. A remote attacker can extract AES keys from multithreaded programs and use them to decrypt traffic. 

Mitigation
Install updates from vendor's website.

Vulnerable software versions

mbed TLS: 3.0.0, 3.1.0, 3.2.0, 3.2.1, 3.3.0, 3.4.0, 3.4.1, 3.5.0, 3.5.1, 3.5.2, 3.6.0, 3.6.1, 3.6.2, 3.6.3

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External links
https://github.com/Mbed-TLS/mbedtls-docs/blob/main/security-advisories/mbedtls-security-advisory-2025-06-1.md

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Q & A

Can this vulnerability be exploited remotely?

Yes. This vulnerability can be exploited by a remote non-authenticated attacker via the Internet.

Is there known malware, which exploits this vulnerability?

No. We are not aware of malware exploiting this vulnerability.