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2002 Views 4 Replies Latest reply: Mar 26, 2012 6:30 PM by Paul Stewart - CCIE Security, CCSI RSS

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Vulnerabilities in my ASA

Mar 23, 2012 12:40 PM

CCIE_2B 124 posts since
Nov 5, 2009

I run a PCI scan in my Fireall and I got this vulnerabilities

 

- OpenSSL SSL_OP_NETSCAPE_REUSE_CIPHER_CHANGE_BUG

 

THREAT: Netscape's SSLv3 implementation had a bug where if a SSLv3 connection is initially established, the first available cipher is used. If a session is

resumed, a different cipher may be chosen if it appears in the passed cipher list before the session's current cipher. This bug can be used to change

ciphers on the server.

OpenSSL contains this bug if the SSL_OP_NETSCAPE_REUSE_CIPHER_CHANGE_BUG option is enabled during runtime. This option was

introduced for compatibility reasons.

The problem arises when different applications using OpenSSL's libssl library enable all compatibility options including

SSL_OP_NETSCAPE_REUSE_CIPHER_CHANGE_BUG, thus enabling the bug.

IMPACT:

A malicious legitimate client can enforce a ciphersuite not supported by the server to be used for a session between the client and the server. This

can result in disclosure of sensitive information.

SOLUTION:

Patch:

This bug appears to be fixed in OpenSSL 0.9.8j and later. Refer to Changes between 0.9.8i and 0.9.8j at OpenSSL Changelog to obtain additional

details. The latest version of OpenSSL is available for download at OpenSSL Download Page.

Workaround:

This problem can be fixed by disabling the SSL_OP_NETSCAPE_REUSE_CIPHER_CHANGE_BUG option from the options list of OpenSSL's libssl

library. This can be done by replacing the SSL_OP_ALL definition in the openssl/ssl.h file with the following line:

 

 

how can I solve this.

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