Multiple vulnerabilities in Mbed TLS

Published: 2025-03-25

Risk	Medium
Patch available	YES
Number of vulnerabilities	2
CVE-ID	CVE-2025-27809 CVE-2025-27810
CWE-ID	CWE-295 CWE-287
Exploitation vector	Network
Public exploit	N/A
Vulnerable software	mbed TLS Universal components / Libraries / Libraries used by multiple products
Vendor	ARM

Security Bulletin

This security bulletin contains information about 2 vulnerabilities.

1) Improper certificate validation

EUVDB-ID: #VU106010

Risk: Medium

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

CVE-ID: CVE-2025-27809

CWE-ID: CWE-295 - Improper Certificate Validation

Exploit availability: No

Description

The vulnerability allows a remote attacker to perform MitM attack.

The vulnerability exists within the client authentication process during certificate-based authentication. Due to insecure default behavior, if a TLS client application does not call mbedtls_ssl_set_hostname(), the server verification step is skipped. As a result, a remote attacker can supply any valid certificate signed by a trusted CA and perform MitM attack.

Mitigation

Install updates from vendor's website.

Vulnerable software versions

mbed TLS: 2.7.18 - 3.6.2

CPE2.3

External links

https://github.com/ARMmbed/mbedtls/releases/tag/mbedtls-2.28.10
https://github.com/ARMmbed/mbedtls/releases/tag/mbedtls-3.6.3
https://mbed-tls.readthedocs.io/en/latest/security-advisories/mbedtls-security-advisory-2025-03-1/

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.

2) Improper authentication

EUVDB-ID: #VU106011