SB2018103027 - Red Hat update for openssl



SB2018103027 - Red Hat update for openssl

Published: October 30, 2018

Security Bulletin ID SB2018103027
Severity
Low
Patch available
YES
Number of vulnerabilities 5
Exploitation vector Remote access
Highest impact Denial of service

Breakdown by Severity

Low 100%
  • Low
  • Medium
  • High
  • Critical

Description

This security bulletin contains information about 5 secuirty vulnerabilities.


1) Out-of-bounds read (CVE-ID: CVE-2017-3735)

The vulnerability allows a remote attacker to perform spoofing attack.

The vulnerability exists due to one-byte out-of-bounds read when parsing an IPAddressFamily extension in an X.509 certificate. A remote attacker can disguise text display of the certificate.


2) Memory-cache side-channel attack (CVE-ID: CVE-2018-0495)

The vulnerability allows a local attacker to obtain potentially sensitive information.

The vulnerability exists due to a leakage of information through memory caches when the affected library uses a private key to create Elliptic Curve Digital Signature Algorithm (ECDSA) signatures.  A local attacker can conduct a memory-cache side-channel attack on ECDSA signatures and recover sensitive information, such as ECDSA private keys, which could be used to conduct further attacks. 

Note: The vulnerability is known as the "Return Of the Hidden Number Problem" or ROHNP.


3) Improper input validation (CVE-ID: CVE-2018-0732)

The vulnerability allows a remote attacker to cause DoS condition on the target system.

The vulnerability exists due to improper handling of large prime values by the affected software during key agreement operations in a Transport Layer Security (TLS) handshake using an Ephemeral Diffie-Hellman (DHE) based cipher suite. A remote attacker can send a large prime value from a malicious OpenSSL server to a targeted OpenSSL client and cause the client to stop responding while generating a key for the prime value.


4) Information disclosure (CVE-ID: CVE-2018-0737)

The vulnerability allows a local attacker to obtain potentially sensitive information on the target system.

The weakness exists in the RSA key generation algorithm's BN_mod_inverse() and BN_mod_exp_mont() functions due to a cache timing side channel attack. A local attacker can recover the private key.

5) Resource exhaustion (CVE-ID: CVE-2018-0739)

The vulnerability allows a remote attacker to cause DoS condition on the target system.

The weakness exists due to excessive stack memory consumption. A remote attacker can cause the service to crash.

Remediation

Install update from vendor's website.