SB2017012701 - Multiple vulnerabilities in OpenSSL

CSH
CYBERSECURITY HELP
Sign In REGISTER

Main Vulnerability Database SB2017012701

SB2017012701 - Multiple vulnerabilities in OpenSSL

Published: January 27, 2017

Security Bulletin ID SB2017012701
Severity
Medium
Patch available
YES
Number of vulnerabilities 3
Exploitation vector Remote access
Highest impact Denial of service

Breakdown by Severity

Medium 33% Low 67%
  • Low
  • Medium
  • High
  • Critical

Description

This security bulletin contains information about 3 secuirty vulnerabilities.


1) Information disclosure (CVE-ID: CVE-2017-3732)

The vulnerability allows a remote attacker to gain access to potentially sensitive information.

The vulnerability exists due to propagating error in the x86_64 Montgomery squaring procedure. A remote attacker with access to unpatched vulnerable system that uses a shared private key with Diffie-Hellman (DH) parameters set can gain unauthorized access to sensitive private key information.

According to vendor’s advisory, this vulnerability is unlikely to be exploited in real-world attacks, as it requires significant resources and online access to an unpatched system using the target private key in a scenario with persistent DH parameters and a private key that is shared between multiple clients.

Vulnerability exploitation against RSA and DSA as a result of this defect would be very difficult to perform and are not believed likely.


2) NULL pointer dereference (CVE-ID: CVE-2017-3730)

The vulnerability allows a remote attacker to cause denial of service.

The vulnerability exists in OpenSSL due to NULL pointer dereference error when processing specially crafted parameters for a Diffie-Hellman Key Exchange (DHE) or Elliptic Curve Diffie-Hellman Exchange (ECDHE), received from malicious server. A remote attacker can trick the victim into connecting to a specially crafted website and trigger NULL pointer dereference error in client software.

Successful exploitation of the vulnerability may allow an attacker to perform denial of service (DoS) attack against vulnerable client software.


3) Out-of-bounds read (CVE-ID: CVE-2017-3731)

The vulnerability allows a remote attacker to cause denial of service conditions.

The vulnerability exists due to out-of-bounds read in OpenSSL when processing truncated packets on 32-bit system using certain ciphers. A remote attacker can send a specially crafted truncated packet using CHACHA20/POLY1305 cipher for OpenSSL 1.1.0 or RC4-MD5 for 1.0.2 and trigger denial of service.

Successful exploitation of the vulnerability may allow an attacker to perform denial of service (DoS) attack against vulnerable system.


Remediation

Install update from vendor's website.

References