CVE-2011-3210: Medium severity openssl vulnerability

Published Sep 6, 2011

Updated

From the upstream advisory [1]:

OpenSSL server code for ephemeral ECDH ciphersuites is not thread-safe, and furthermore can crash if a client violates the protocol by sending handshake messages in incorrect order. (CVE-2011-3210)

This issue applies to OpenSSL 0.9.8 through 0.9.8s (experimental "ECCdraft" ciphersuites) and to OpenSSL 1.0.0 through 1.0.0d.

Affected users of OpenSSL should update to the OpenSSL 1.0.0e release, which contains a patch to correct this issue. If you cannot immediately upgrade, we recommend that you disable ephemeral ECDH ciphersuites if you have enabled them.

Thanks to Adam Langley <agl> for identifying and fixing this issue.

Only server-side applications that specifically support ephemeral ECDH ciphersuites are affected by the ephemeral ECDH crash bug and only if ephemeral ECDH ciphersuites are enabled in the configuration. You can check to see if application supports ephemeral ECDH ciphersuites by looking for SSLCTXsettmpecdh, SSLsettmpecdh, SSLCTRLSETTMPECDH, SSLCTXsettmpecdhcallback, SSLsettmpecdhcallback, SSLCTRLSETTMPECDHCB in the source code.

[1] http://www.openssl.org/news/secadv20110906.txt

Statement:

Not vulnerable. This issue did not affect the versions of openssl as shipped with Red Hat Enterprise Linux 3, 4, 5, or 6, as they do not include the support for the elliptic curve cryptography.

Other sources

The ephemeral ECDH ciphersuite functionality in OpenSSL 0.9.8 through 0.9.8r and 1.0.x before 1.0.0e does not ensure thread safety during processing of handshake messages from clients, which allows remote attackers to cause a denial of service (daemon crash) via out-of-order messages that violate the TLS protocol.

— MITRE

Affected Software

30 affected components

OpenSSL OpenSSL=0.9.8

OpenSSL OpenSSL=0.9.8a

OpenSSL OpenSSL=0.9.8b

OpenSSL OpenSSL=0.9.8c

OpenSSL OpenSSL=0.9.8d

OpenSSL OpenSSL=0.9.8e

OpenSSL OpenSSL=0.9.8f

OpenSSL OpenSSL=0.9.8g

OpenSSL OpenSSL=0.9.8h

OpenSSL OpenSSL=0.9.8i

OpenSSL OpenSSL=0.9.8j

OpenSSL OpenSSL=0.9.8k

OpenSSL OpenSSL=0.9.8l

OpenSSL OpenSSL=0.9.8m

OpenSSL OpenSSL=0.9.8n

OpenSSL OpenSSL=0.9.8o

OpenSSL OpenSSL=0.9.8p

OpenSSL OpenSSL=0.9.8q

OpenSSL OpenSSL=0.9.8r

OpenSSL OpenSSL=0.9.8s

OpenSSL OpenSSL=1.0.0

OpenSSL OpenSSL=1.0.0-beta1

OpenSSL OpenSSL=1.0.0-beta2

OpenSSL OpenSSL=1.0.0-beta3

OpenSSL OpenSSL=1.0.0-beta4

OpenSSL OpenSSL=1.0.0-beta5

OpenSSL OpenSSL=1.0.0a

OpenSSL OpenSSL=1.0.0b

OpenSSL OpenSSL=1.0.0c

OpenSSL OpenSSL=1.0.0d

Remediation

Patch Available

http://cvs.openssl.org/chngview?cn=21337

Event History

Sep 6, 2011

Data Sourced

03:44 PM

DescriptionSeverityAffected Software

Sep 22, 2011

CVE Published

via MITRE·10:00 AM

Data Sourced

via MITRE·10:00 AM

Description

Frequently Asked Questions

What is the severity of CVE-2011-3210?

CVE-2011-3210 has a moderate severity rating due to potential crashes caused by incorrect protocol use during handshakes.

What versions of OpenSSL are affected by CVE-2011-3210?

OpenSSL versions 0.9.8a to 1.0.0d are affected by CVE-2011-3210.

How do I fix CVE-2011-3210?

To fix CVE-2011-3210, upgrade to a patched version of OpenSSL higher than 1.0.0d.

What are the risks associated with CVE-2011-3210?

The risks of CVE-2011-3210 include application crashes and potential denial of service vulnerability.

Is CVE-2011-3210 a client or server issue?

CVE-2011-3210 is primarily a server-side issue related to the handling of ECDH ciphersuites in OpenSSL.