A security vulnerability in the TLS protocol (TLS 1.0 or later and SSLv3) may allow an unauthenticated, remote attacker to conduct man-in-the-middle (MITM) type of attacks where chosen plain text may be injected as a prefix in an user's TLS session. This vulnerability does not allow one to decrypt or modify the intercepted network communication.

This issue is referenced in CVE-2009-3555 and US-CERT VU#120541

Exact nature of the impact depends on the application making use of the TLS facility.

Sun is evaluating the impact of the issue on various products which make use of the TLS libraries. We are working to fix the TLS implementations according to the TLS protocol standard extensions currently being developed.

• Solaris Kernel SSL:
  Solaris Kernel SSL proxy module KSSL does not support client renegotiation or rehandshake. It ignores the rehandshake message which is an allowed behavior by the SSL/TLS specification. Hence it is not vulnerable to this issue. KSSL (see ksslcfg(1M)) is available in Solaris 10 and OpenSolaris. It may be used to workaround the described issue in server applications.

• Java:
  The Java Secure Socket Extension (JSSE) included in the following Java SE and Java SE for Business releases for Windows, Solaris, and Linux are affected:

  • JDK and JRE 6 Update 17 and earlier
  • JDK and JRE 5.0 Update 22 and earlier
  • SDK and JRE 1.4.2_24 and earlier

  An interim fix, that disables TLS/SSL renegotiation in JSSE by default, will be included in our upcoming Java SE security update. Once the industry (via IETF-TLS Working Group) standardizes a fix to the protocol, Sun will update this fix accordingly.

• GnuTLS libraries in Solaris:
  The issue does not affect any server applications distributed with Solaris which use the GnuTLS library. At this time we do not plan to issue any interim fixes to GnuTLS libraries. Fixes to GnuTLS distributed with Solaris would be provided when the proposed TLS extensions become a standard.

• OpenSSL libraries in Solaris:
  Sun Alert 273029 describes this issue in OpenSSL (openssl(5)) libraries provided with in Solaris 10 and OpenSolaris.

• Network Security Services (NSS):
  Sun Alert 273350 describes the issue in NSS libraries provided with Solaris and Sun Java Enterprise System.

• Sun Java Enterprise System Suite
  Sun Alert 274990 describes the issue in Sun Java System Web Server 6.1, 7.0, Sun Java System Web Proxy Server 4.0, Sun Java System Application Server Enterprise Edition and Sun GlassFish Enterprise Server v2.1. This article explains the issue in Sun Java System Web Server and provides workarounds and mitigation.

tags: gnutls jsse nss openssl security tls vulnerability