OpenSSL: Information Disclosure

Background

OpenSSL is an Open Source toolkit implementing the Secure Sockets Layer (SSL v2/v3) and Transport Layer Security (TLS v1) as well as a general purpose cryptography library.

Description

Multiple vulnerabilities have been found in OpenSSL:

• OpenSSL incorrectly handles memory in the TLS heartbeat extension, leading to information disclosure of 64kb per request, possibly including private keys (“Heartbleed bug”, OpenSSL 1.0.1 only, CVE-2014-0160).
• The Montgomery ladder implementation of OpenSSL improperly handles swap operations (CVE-2014-0076).

Impact

A remote attacker could exploit these issues to disclose information, including private keys or other sensitive information, or perform side-channel attacks to obtain ECDSA nonces.

Workaround

Disabling the tls-heartbeat USE flag (enabled by default) provides a workaround for the CVE-2014-0160 issue.

Resolution

All OpenSSL users should upgrade to the latest version:

 # emerge --sync
 # emerge --ask --oneshot --verbose ">=dev-libs/openssl-1.0.1g"

Note: All services using OpenSSL to provide TLS connections have to be restarted for the update to take effect. Utilities like app-admin/lib_users can aid in identifying programs using OpenSSL.

As private keys may have been compromised using the Heartbleed attack, it is recommended to regenerate them.