웹브라우저와 서버 간의 통신을 암호화하는 오픈소스 라이브러리인 'OpenSSL'에 심각한 취약점이 발견되어 즉각적인 업데이트가 필요하다고 10일 밝혔다. 취약점이 발견된 버전은 OpenSSL 1.0.1 ~ 1.0.1f 및 OpenSSL 1.0.2-beta, 1.0.2-beta1이다.

이 취약점은 허트블리드(HeartBleed)로 명명되고 있으며, 해당 취약점을 악용할 경우 웹서버로 전송된 개인정보, 비밀번호 등은 물론 웹서버의 암호키도 탈취될 수 있다.

해당 취약점을 해결하기 위해서는 OpenSSL 공식홈페이지(www.openssl.org)에 접속해 지난 7일에 배포된 OpenSSL 1.0.1g 버전으로 업데이트를 해야 한다. OpenSSL은 주로 공개용 웹서버 프로그램인 아파치(Apache) 또는 엔진엑스(Nginx)와 함께 사용되는 경우가 많아 이를 사용하는 경우 특히 OpenSSL의 버전을 확인하고 조치해야 한다.

-------------

CAcert is not responsible for this issue. But we want to inform members  about it, who are especially likely to be vulnerable or otherwise affected.

Good news:
==========
Certificates issued by CAcert are not broken and our central systems did not leak your keys.

Bad news:
=========
Even then you may be affected.

Although your keys were not leaked by CAcert your keys on your own systems  might have been compromised if you were or are running a vulnerable version of OpenSSL.

To elaborate on this:
=====================
The central systems of CAcert and our root certificates are not affected by
this issue. Regrettably some of our infrastructure systems were affected by
the bug. We are working to fix them and already completed work for the most
critical ones. If you logged into those systems, within the last two years,
(see list in the blog post) you might be affected!

But unfortunately given the nature of this bug we have to assume that the
certificates of our members may be affected, if they were used in an
environment with a publicly accessible OpenSSL connection (e.g. Apache web
server, mail server, Jabber server, ...). The bug has been open in OpenSSL
for two years - from December 2011 and was introduced in stable releases
starting with OpenSSL 1.0.1.

When an attacker can reach a vulnerable service he can abuse the TLS
heartbeat extension to retrieve arbitrary chunks of memory by exploiting a
missing bounds check. This can lead to disclosure of your private keys,
resident session keys and other key material as well as  all volatile
memory contents of the server process like passwords, transmitted user data
(e.g. web content) as well as other potentially confidential information.

Exploiting this bug does not leave any noticeable traces, thus for any
system which is (or has been) running a vulnerable version of OpenSSL you
must assume  that at least your used server keys are compromised and
therefore must be replaced by newly generated ones. Simply renewing
existing certificates is not sufficient! - Please generate NEW keys with at
least 2048 bit RSA or stronger!

As mentioned above this bug can be used to leak passwords and thus you
should consider changing your login credentials to potentially compromised
systems as well as any other system where those credentials might have been
used as soon as possible.

An (incomplete) list of commonly used software which include or link to
OpenSSL can be found at [5].

What to do?
===========
- Ensure that you upgrade your system to a fixed OpenSSL version (1.0.1g or
above).
- Only then create new keys for your certificates.
- Revoke all certificates, which may be affected.
- Check what services you have used that may have been affected within the
last two years.
- Wait until you think that those environments got fixed.
- Then (and only then) change your credentials for those services. If you
do it too early, i.e. before the sites got fixed, your data may be leaked,
again. So be careful when you do this.