FREAK Attack
On
Tuesday, March 3, 2015, researchers announced a new SSL/TLS
vulnerability called the FREAK attack. It allows an attacker to
intercept HTTPS connections between vulnerable clients and servers
and force them to use weakened encryption, which the attacker can
break to steal or manipulate sensitive data. This site is dedicated
to tracking the impact of the attack and helping users test whether
they’re vulnerable.
The FREAK
attack was discovered by
Karthikeyan Bhargavan at INRIA in Paris and the miTLS
team. Further disclosure was coordinated by Matthew Green. This
report is maintained by computer scientists at the University of
Michigan, including Zakir Durumeric, David Adrian, Ariana Mirian,
Michael Bailey, and J. Alex Halderman.
Who is vulnerable?
The FREAK
attack is possible when a vulnerable browser connects to a
susceptible web server—a server that accepts “export-grade”
encryption.
Servers
Servers
that accept RSA_EXPORT cipher suites put their users at risk from the
FREAK attack. Using Internet-wide scanning, we have been performing
daily tests of all HTTPS servers at public IP addresses to determine
whether they allow this weakened encryption. More than a third of all
servers with browser-trusted certificates are at risk.
|
Currently
Vulnerable
|
Change Since
Mar. 3
|
HTTPS servers at Alexa
Top 1 Million domain names |
9.5% |
down from 12.2% |
HTTPS servers with
browser-trusted certificates |
36.7% |
unchanged |
All HTTPS servers |
26.3% |
unchanged
|
See below
for a list of vulnerable
popular domains. You can test servers using the SSL
FREAK Check tool or the Qualys SSL Labs’ SSL
Server Test, which can also identify other security problems.
Clients
Update
(Mar. 5):
Browsers are vulnerable to the FREAK attack because of bugs that
allow an attacker to force them to use weak, export-grade encryption.
One example is the OpenSSL bug described in CVE-2015-0204,
but some other TLS libraries have similar problems. Far more browsers
are vulnerable to the FREAK attack than was initially thought when
the attack was announced, including:
Vulnerable Browser |
Status |
Internet Explorer |
Patch
available now — Security
advisory |
Chrome on Mac OS |
Patch available now |
Chrome on Android |
|
Safari on Mac OS |
Patch
available now |
Safari on iOS |
iOS
8 Patch available now |
Stock Android Browser |
|
Blackberry Browser |
|
Opera on Mac OS |
Patch available now |
Chrome
for Windows and all modern versions of Firefox are known to be safe.
However, even if your browser is safe, certain third-party software,
including some anti-virus products and adware programs, can expose
you to the attack by intercepting TLS connections from the browser.
If you are using a safe browser but our client test says you’re
vulnerable, this is a likely cause.
In
addition to browsers, many mobile apps, embedded systems, and other
software products also use TLS. These are also potentially vulnerable
if they rely on unpatched libraries or offer RSA_EXPORT cipher
suites.
What should you do?
If you run a server …
You
should immediately disable support for TLS export cipher suites.
While you’re at it, you should also disable other cipher suites
that are known to be insecure and enable forward secrecy. For
instructions on how to secure popular HTTPS server software, we
recommend Mozilla’s security
configuration guide and their SSL
configuration generator. We also recommend testing your
configuration with the Qualys SSL Labs SSL
Server Test tool.
If you use a browser …
Make sure
you have the most recent version of your browser installed, and check
for updates frequently. Updates that fix the FREAK attack should be
available for all major browsers soon.
If you’re a sysadmin or developer …
Make sure
any TLS libraries you use are up to date. Unpatched OpenSSL,
Microsoft
Schannel, and Apple Secure Transport all suffer from the
vulnerability. Note that these libraries are used internally by many
other programs, such as wget
and curl.
You also need to ensure that your software does not offer export
cipher suites, even as a last resort, since they can be exploited
even if the TLS library is patched. We have provided tools
for software developers that may be helpful for testing.
for
vulnerable sites go to this link freak
attack
Comments
Post a Comment