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17 votes

Is gzipping content via TLS allowed?

I read that this should be avoided because of CRIME/BREACH attack, is this correct? It depends. The CRIME attack is already mitigated in current browsers in that they don't use TLS compression and ...
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11 votes
Accepted

Prevent BEAST attack without RC4 cipher suites

BEAST is a client-side attack, so all you can do on the server side is to avoid letting unaware clients put themselves in a BEAST-vulnerable position. However, modern clients (Web browsers) are not ...
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5 votes
Accepted

Is there a vulnerability when TLS is decrypted, then encrypted with OpenSSL that is vulnerable to BEAST or CRIME?

BEAST is a vulnerability on the client, not on the server. A server is not, and never has been, "vulnerable to BEAST". There is some confusion about tools that "test SSL servers", that may report a "...
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4 votes

BEAST attack on TSL1.2?

Paypal supports TLS 1.0, 1.1, and 1.2. If your browser advertises that it would like to use TLS 1.2, then that is indeed the TLS version that Paypal will choose to connect with. If, however, your ...
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  • 35.5k
4 votes

Do the BEAST and CRIME attacks apply to an IMAP service?

CRIME and BEAST are chosen-ciphertext attacks. The attacker needs to send tens of thousands of requests in the connection of the user. This works well for a web browser. Theoretically, it is possible ...
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  • 389
2 votes

Is AES-GCM recommended for SSL?

I realize the post is from 2013, but I happened upon this post when researching a patch for the latest openSSL vulnerability announced 3 May 2016 (Info - https://www.openssl.org/news/secadv/20160503....
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  • 121
2 votes
Accepted

Beast attack and Qualys SSL test

SSL Labs no longer penalizes this In a blog post dated 2013-09-10 SSL Labs project lead Ivan Ristic said: Yesterday I changed the SSL Labs rating criteria to stop penalizing sites that do not ...
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2 votes

Is gzipping content via TLS allowed?

gzipping SSL-encrypted data eliminates the advantages of SSL to some extent. Yes, gzipping ALL content might opens your website up to the BREACH-vulnerability. But you can still add some resources ...
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  • 71
2 votes

CRIME attack - If Javascript can be injected on the attacked machine, why not directly sending the cookie to a remove server?

Because the JavaScript will be running from a different origin - the Same Origin Policy will prevent example.org from grabbing the cookies from bank.example.com. Example.org does not even have to ...
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1 vote
Accepted

Are disabling TLS 1.0, enabling RC4 or using TLS1.0 with AES only, the only ways to mitigate BEAST server-side?

Yes. Several years ago, Qualys covered mitigation techniques, and notably several methods that you might think would work (like "enabling the empty fragment technique server-side") are ineffective ...
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1 vote
Accepted

Detecting POODLE and BEAST using nmap

So, if the server's preferred cipher is RC4 and client provides a CBC cipher (Only one) will it select CBC or rejects the request? If the server supports the CBC cipher that the client provides, the ...
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1 vote

CRIME attack - If Javascript can be injected on the attacked machine, why not directly sending the cookie to a remove server?

In addition to Neil's answer if a cookie is marked as HttpOnly it will be inaccessible via javascript and therefore you cannot pass it on to the evil server.
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  • 2,802
1 vote

CRIME attack - If Javascript can be injected on the attacked machine, why not directly sending the cookie to a remove server?

The JavaScript is not injected on bank.com, it's run on compromised.com that you visit or are tricked into visiting. The JavaScript on compromised.com makes requests to bank.com on your behalf. The ...
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1 vote

BEAST some misunderstandings

Yes Pi is appended to the body; (re)read the paragraph labelled Blockwise Privilege at the top of the page. Remember HTTP and thus HTTPS is a stream protocol; if you make a request to upload say 100 ...
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1 vote

Is RDP susceptible to the BEAST attack?

A few things: You might be interested in this link: - seems PCI compliance scanners get confused about these issues sometimes. Technically Beast applies to Browsers, but CBC is not what you want ...
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  • 2,020
1 vote

Hardened SSL ciphers for Nginx as AWS/Cloudfront Custom Origin

For what it's worth, John Hardin's answer was correct when written, but there has been some good news. In August 2014, AWS announced support for new AES cipher suites, including the nice ECDHE ones ...
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1 vote

How to fix SSL 2.0 and BEAST on IIS

disabling everything "RC4" with IIS Crypto allowed to pass PCI compliance test on Server 2008 / IIS 7.0
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