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Vulnerability Spotlight: ARM Mbedtls x509 ECDSA invalid public key Code Execution Vulnerability

highVulnerability exploited in the wildimportance 60CVE-2017-2784

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CVEVulnerabilityCVSSEPSSFlagsAffectedExposurePublished
CVE-2017-2784
An exploitable free of a stack pointer vulnerability exists in the x509 certificate parsing code of ARM mbed TLS before 1.3.19, 2.x before 2.1.7, and 2.4.x befo

An exploitable free of a stack pointer vulnerability exists in the x509 certificate parsing code of ARM mbed TLS before 1.3.19, 2.x before 2.1.7, and 2.4.x before 2.4.2. A specially crafted x509 certificate, when parsed by mbed TLS library, can cause an invalid free of a stack pointer leading to a potential remote code execution. In order to exploit this vulnerability, an attacker can act as either a client or a server on a network to deliver malicious x509 certificates to vulnerable applications.

NVD description · AI analysis pending
8.13% PoC
  • trustedfirmware mbed tls
Full article231 words · extracted from blog.talosintelligence.com · click to collapse

Wednesday, April 19, 2017 10:33

Vulnerability Discovered by Aleksandar Nikolic

Overview

Talos is disclosing TALOS-2017-0274/CVE-2017-2784, a code execution vulnerability in ARM MbedTLS. This vulnerability is specifically related to how MbedTLS handles x509 certificates. MbedTLS is an SSL/TLS implementation aimed specifically at embedded devices that was previously known as PolarSSL.

The vulnerability exists in the part of the code responsible for handling elliptic curve cryptography keys. An attacker can trigger this vulnerability by providing a specially crafted x509 certificate to the target which performs a series of checks on the certificate. While performing these checks the application fails to properly parse the public key. This results in the invalid free of a stack pointer. There is a mitigating factor associated with this vulnerability in that the memory space that is pointed to is zeroed out shortly before the vulnerability is triggered. However, since it's designed to be used in embedded platforms that may not have modern heap exploitation mitigations in place it may be possible to achieve code execution in certain circumstances.  Full details of the vulnerability are available in our advisory.

Coverage

The following Snort Rules will detect exploitation attempts. Note that additional rules may be released at a future date and current rules are subject to change pending additional vulnerability information. For the most current rule information, please refer to your FireSIGHT Management Center or Snort.org.

Snort Rules: 41364

Text extracted automatically; images, tables and formatting may be missing. Original: https://blog.talosintelligence.com/vulnerability-spotlight-arm-tls/