GLSA 201603-15: OpenSSL: Multiple vulnerabilities

http://security.gentoo.org/

Severity:	normal
Title:	OpenSSL: Multiple vulnerabilities
Date:	03/20/2016
Bugs:	#575548
ID:	201603-15

Synopsis

Multiple vulnerabilities have been found in OpenSSL, the worst allowing remote attackers to decrypt TLS sessions.

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.

Affected packages

Package	Vulnerable	Unaffected	Architecture(s)
dev-libs/openssl	< 1.0.2g-r2	>= 1.0.2g-r2	All supported architectures

Description

Multiple vulnerabilities have been discovered in OpenSSL, the worst being a cross-protocol attack called DROWN that could lead to the decryption of TLS sessions. Please review the CVE identifiers referenced below for details.

Impact

A remote attacker could decrypt TLS sessions by using a server supporting SSLv2 and EXPORT cipher suites as a Bleichenbacher RSA padding oracle, cause a Denial of Service condition, obtain sensitive information from memory and (in rare circumstances) recover RSA keys.

Workaround

A workaround for DROWN is disabling the SSLv2 protocol on all SSL/TLS servers.

Resolution

All OpenSSL users should upgrade to the latest version:

      # emerge --sync
      # emerge --ask --oneshot --verbose ">=dev-libs/openssl-1.0.2g-r2"

Please note that beginning with OpenSSL 1.0.2, in order to mitigate the DROWN attack, the OpenSSL project disables SSLv2 by default at build-time. As this change would cause severe issues with some Gentoo packages that depend on OpenSSL, Gentoo still ships OpenSSL with SSLv2 enabled at build-time. Note that this does not mean that you are still vulnerable to DROWN because the OpenSSL project has taken further precautions and applications would need to explicitly request SSLv2. We are working on a migration path to phase out SSLv2 that ensures that no user-facing issues occur. Please reference bug 576128 for further details on how this decision was made.

References

Availability

This GLSA and any updates to it are available for viewing at the Gentoo Security Website: http://security.gentoo.org/glsa/glsa-201603-15.xml

Concerns?

Security is a primary focus of Gentoo Linux and ensuring the confidentiality and security of our users machines is of utmost importance to us. Any security concerns should be addressed to security@gentoo.org or alternatively, you may file a bug at https://bugs.gentoo.org.