000030937 - RSA BSAFE Toolkits: Key Compromise Impersonation (KCI) attacks against TLS

Document created by RSA Customer Support Employee on Jun 14, 2016
Version 1Show Document
  • View in full screen mode

Article Content

Article Number000030937
Applies ToAffected Product and Versions:
RSA BSAFE Micro Edition Suite (MES), all versions prior to 4.0.8 and prior to 4.1.4
RSA BSAFE SSL-J, all versions
Unaffected Product and Versions:
RSA BSAFE Crypto-C ME, all versions
RSA BSAFE Crypto-J, all versions
RSA BSAFE Cert-J, all versions
RSA BSAFE SSL-C, all versions
RSA BSAFE Crypto-C, all versions
RSA BSAFE Share Adapter, all versions
OSAll Operating Systems
CVE IDTBD
Article SummaryOn August 10th, 2015, a practical attack was publicly announced against the TLS protocol when certain cipher suites are used. More details are provided below.
Link to AdvisoriesThe research paper is available here: https://www.usenix.org/conference/woot15/workshop-program/presentation/hlauschek
NVD Advisory: TBD
OpenSSL Advisory: TBD
Technical Details ExplanationOn August 10th, 2015, a practical attack was publicly announced against the TLS protocol when certain cipher suites are used. The researchers at RISE (Research Industrial System Engineering GmbH) discovered a Key Compromise Impersonation (KCI) attack against the TLS protocol. The KCI is a form of the Man in the Middle (MitM) attack where an attacker can impersonate a TLS client and/or TLS server when fixed DH and fixed ECDH cipher suites are used.
In order to successfully carry out the KCI attack, the attacker needs to install a malicious server certificate, to which they know the private key, into the certificate trust store on the client host (the victim’s machine).  To install a malicious server certificate on a victim’s machine, the attacker has to compromise the machine in some manner (i.e. by exploiting another vulnerability or by infecting the machine with a Trojan or some other malware).
For a particular client/server connection, the client will only be vulnerable if the server is using an ECC certificate and requires or supports client authentication.
The table below provides an overview of the impact of this issue on RSA BSAFE products:

 
ProductImpactMitigation
BSAFE SSL-JImpacted if a fixed DH or fixed ECDH cipher suite is used for TLS. These cipher suites are supported in the product but they are not enabled by default.
  
   For a particular client/server connection, the client will only be vulnerable if the server is using an ECC certificate and requires or supports client authentication.
Do not use fixed DH and fixed ECDH cipher suites.  Any cipher suites for ECDH-ECDSA-*, ECDH-RSA-*, DH-RSA-* or DH-DSS-* should be disabled in client and server configurations. See product documentation for instructions on how to inspect and change cipher lists manually. 
   These cipher suites are not included in the default lists for the current releases of SSL-J.
BSAFE MESImpacted if a fixed DH or fixed ECDH cipher suite is used for TLS.
  
   For a particular client/server connection, the client will only be vulnerable if the server is using an ECC certificate and requires or supports client authentication.
Do not use fixed DH and fixed ECDH cipher suites.  Any cipher suites for ECDH-ECDSA-* or ECDH-RSA-* should be disabled in client and server configurations. See product documentation for instructions on how to inspect and change cipher lists manually. 
   The affected cipher suites have been removed from the default lists for BSAFE MES v4.0.8.
BSAFE SSL-CNot impacted because there is no support for these cipher suites.N/A
BSAFE Crypto-JNot impacted because this product does not implement the SSL/TLS protocols.N/A
BSAFE Cert-JNot impacted because this product does not implement the SSL/TLS protocols.N/A
BSAFE Crypto-C MENot impacted because this product does not implement the SSL/TLS protocols.N/A
Share AdapterNot impacted because there is no support for static DH cipher suites, and the SSL/TLS API does not allow the use of ECC certificates and keys preventing use of the static ECDH cipher suites that were not officially supported.N/A

 

Disclaimer

Read and use the information in this RSA Security Advisory to assist in avoiding any situation that might arise from the problems described herein. If you have any questions regarding this product alert, contact RSA Software Technical Support at 1- 800 995 5095. RSA Corporation distributes RSA Security Advisories, in order to bring to the attention of users of the affected RSA products, important security information. RSA recommends that all users determine the applicability of this information to their individual situations and take appropriate action. The information set forth herein is provided 'as is' without warranty of any kind. RSA disclaims all warranties, either express or implied, including the warranties of merchantability, fitness for a particular purpose, title and non-infringement. In no event, shall RSA or its suppliers, be liable for any damages whatsoever including direct, indirect, incidental, consequential, loss of business profits or special damages, even if RSA or its suppliers have been advised of the possibility of such damages. Some states do not allow the exclusion or limitation of liability for consequential or incidental damages, so the foregoing limitation may not apply.

Attachments

    Outcomes