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Questions tagged [logjam]

Logjam is a vulnerability in TLS implementations. It targets the Diffie-Hellman key exchange and allows downgrading the security if the server supports weak DH keys.

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Command to check a website is vulnerable to Logjam

I am referring this post https://www.openssl.org/blog/blog/2015/05/20/logjam-freak-upcoming-changes/ and trying to see a website is vulnerable to Logjam or not. I try with www.google.com:443 but I am ...
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Setup Wireshark to decrypt TLS_DHE

I have a passively sniffed traffic dump of client/server were packets are encrypted with cipher suite Cipher Suite: TLS_DHE_RSA_WITH_AES_128_GCM_SHA256 (0x009e) With a Logjam attack I managed to ...
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Logjam definition question

As I understand it, the Logjam TLS attack is an attack that downgrades the DHE cipher suite used by the server to DHE_EXPORT. Where the client thinks it is talking DHE 512 and the server things it's ...
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Why is Mozilla recommending predefined DHE groups?

In a revision dated 2016-10-31, Mozilla changed their Server Side TLS recommendation from generating a random DH group to the ones published in RFC 7919. Mozilla claims: These groups are audited ...
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Clarification on DH groups

Nikto reports the following via the "ssl-dh-params" NSE script: Check results: | WEAK DH GROUP 1 | Cipher Suite: TLS_DHE_RSA_WITH_AES_256_GCM_SHA384 | Modulus Type: Safe ...
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How can a RSA-2048 certificate be vulnerable to logjam attack? [duplicate]

Most likely I am missing some fundamentals: Our web servers are secured with TLS encryption. We use RSA-2048 bit certificates. The logjam attack targets the DH algorithm. How can our web servers be ...
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Does the recommended course of action for preventing Logjam on Tomcat servers really eliminate all risks of weak DH keys?

Can anyone verify this fix secures against the Logjam vulnerability for Apache Tomcat? I'm sceptical about it's effectiveness, since it doesn't mention how to implement the user defined 2048 bit DH ...