SB2018082806 - Security restrictions bypass in ARM mbed TLS



SB2018082806 - Security restrictions bypass in ARM mbed TLS

Published: August 28, 2018 Updated: December 14, 2020

Security Bulletin ID SB2018082806
CSH Severity
Low
Patch available
YES
Number of vulnerabilities 1
Exploitation vector Remote access
Highest impact Data manipulation

Breakdown by Severity

Low 100%
  • Low
  • Medium
  • High
  • Critical

Description

This security bulletin contains information about 1 vulnerability.


1) Improper certificate validation (CVE-ID: CVE-2018-1000520)

CWE-ID: CWE-295 - Improper Certificate Validation

CVSSv4: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:L/VA:L/SC:N/SI:N/SA:N/E:U/U:Clear


The vulnerability allows a remote attacker to bypass security restrictions on the target system.

The vulnerability exists in the mbedtls_ssl_get_verify_result() function of ARM mbed Transport Layer Security (TLS) due to improper validation of signed certificates. A remote attacker on a peer system can use a negotiated cipher suite of an Elliptic Curve Diffie-Hellman (ECDH) key exchange and Rivest-Shamir-Adleman (RSA) signed certificate (TLS-ECDH-RSA-*) to cause the targeted system to accept an arbitrary ECDSA signed certificate.


Remediation

Install update from vendor's website.