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OpenSSL is vulnerable to a man-in-the-middle attack

Vulnerability Note VU#978508

Original Release Date: 2014-06-05 | Last Revised: 2015-10-27

Overview

OpenSSL is vulnerable to a man-in-the-middle attack.

Description

The OpenSSL security advisory states:

SSL/TLS MITM vulnerability (CVE-2014-0224)
===========================================

An attacker using a carefully crafted handshake can force the use of weak keying material in OpenSSL SSL/TLS clients and servers. This can be exploited by a Man-in-the-middle (MITM) attack where the attacker can decrypt and modify traffic from the attacked client and server.

The attack can only be performed between a vulnerable client *and* server. OpenSSL clients are vulnerable in all versions of OpenSSL. Servers are only known to be vulnerable in OpenSSL 1.0.1 and 1.0.2-beta1. Users of OpenSSL servers earlier than 1.0.1 are advised to upgrade as a precaution.

OpenSSL 0.9.8 SSL/TLS users (client and/or server) should upgrade to 0.9.8za.
OpenSSL 1.0.0 SSL/TLS users (client and/or server) should upgrade to 1.0.0m.
OpenSSL 1.0.1 SSL/TLS users (client and/or server) should upgrade to 1.0.1h.

Thanks to KIKUCHI Masashi (Lepidum Co. Ltd.) for discovering and researching this issue. This issue was reported to OpenSSL on 1st May 2014 via JPCERT/CC.

The fix was developed by Stephen Henson of the OpenSSL core team partly based on an original patch from KIKUCHI Masashi.

Additional details may be found in the OpenSSL security advisory. This vulnerability is one of many that has been fixed in the latest release.

Masashi Kikuchi has written a technical blog post about the vulnerability.

Impact

A remote attacker with a man-in-the-middle vantage point on the network may be able to decrypt or modify traffic between a client and server.

Solution

Apply an Update

OpenSSL 0.9.8 SSL/TLS users (client and/or server) should upgrade to 0.9.8za.
OpenSSL 1.0.0 SSL/TLS users (client and/or server) should upgrade to 1.0.0m.
OpenSSL 1.0.1 SSL/TLS users (client and/or server) should upgrade to 1.0.1h.

Vendor Information

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CVSS Metrics

Group Score Vector
Base 6.4 AV:A/AC:M/Au:N/C:C/I:P/A:N
Temporal 5 E:POC/RL:OF/RC:C
Environmental 8.1 CDP:H/TD:H/CR:H/IR:M/AR:L

References

Acknowledgements

Thanks to KIKUCHI Masashi for reporting this vulnerability.

This document was written by Jared Allar.

Other Information

CVE IDs: CVE-2014-0224
Date Public: 2014-06-05
Date First Published: 2014-06-05
Date Last Updated: 2015-10-27 02:18 UTC
Document Revision: 31

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