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| The SSL version 3 and TLS protocols support session renegotiation without cryptographically tying the new session parameters to the old parameters. |
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Credit:
The information has been provided by Marsh Ray and Steve Dispensa.
The original article can be found at: http://security.FreeBSD.org/advisories/FreeBSD-SA-09:15.ssl.asc
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Vulnerable Systems:
* FreeBSD
An attacker who can intercept a TCP connection being used for SSL or TLS can cause the initial session negotiation to take the place of a session renegotiation. This can be exploited in several ways, including:
* Causing a server to interpret incoming messages as having been sent under the auspices of a client SSL key when in fact they were not;
* Causing a client request to be appended to an attacker-supplied request, potentially revealing to the attacker the contents of the client request (including any authentication parameters); and
* Causing a client to receive a response to an attacker-supplied request instead of a response to the request sent by the client.
NOTE WELL: This update causes OpenSSL to reject any attempt to renegotiate SSL / TLS session parameters. As a result, connections in which the other party attempts to renegotiate session parameters will break. In practice, however, session renegotiation is a rarely-used feature, so disabling this functionality is unlikely to cause problems for most systems.
Perform one of the following:
1) Upgrade your vulnerable system to 6-STABLE, 7-STABLE, or 8-STABLE, or to the RELENG_8_0, RELENG_7_2, RELENG_7_1, RELENG_6_4, or RELENG_6_3 security branch dated after the correction date.
2) To patch your present system:
The following patches have been verified to apply to FreeBSD 6.3, 6.4, 7.1, 7.2, and 8.0 systems.
a) Download the relevant patch from the location below, and verify the detached PGP signature using your PGP utility.
# fetch http://security.FreeBSD.org/patches/SA-09:15/ssl.patch
# fetch http://security.FreeBSD.org/patches/SA-09:15/ssl.patch.asc
b) Execute the following commands as root:
# cd /usr/src
# patch < /path/to/patch
# cd /usr/src/secure/lib/libssl
# make obj && make depend && make includes && make && make install
NOTE: On the amd64 platform, the above procedure will not update the lib32 (i386 compatibility) libraries. On amd64 systems where the i386 compatibility libraries are used, the operating system should instead be recompiled as described in
CVE Information:
CVE-2009-3555
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