Bug 994856

Summary: BREACH attack against HTTPS compression
Product: [Other] Security Response Reporter: Huzaifa S. Sidhpurwala <huzaifas>
Component: vulnerabilityAssignee: Red Hat Product Security <security-response-team>
Status: CLOSED DUPLICATE QA Contact:
Severity: medium Docs Contact:
Priority: medium    
Version: unspecifiedCC: gecko-bugs-nobody, jhorak, jkurik, stransky, webstack-team
Target Milestone: ---Keywords: Security
Target Release: ---   
Hardware: All   
OS: Linux   
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Fixed In Version: Doc Type: Bug Fix
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Last Closed: 2013-08-08 19:08:11 UTC Type: ---
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oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
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Bug Depends On:    
Bug Blocks: 994861    

Description Huzaifa S. Sidhpurwala 2013-08-08 06:53:01 UTC 
It was found that by observing the length of compressed HTTPS responses, an attacker may be able to derive plaintext secrets from the ciphertext of an HTTPS stream. This attack known as BREACH (Browser Reconnaissance and Extration via Adaptive Compression of Hypertext) was demonstrated by researchers at the Blackhat Conference (USA) 2013.

More details about the flaw along with the research paper is available at:

http://breachattack.com/
http://www.kb.cert.org/vuls/id/987798
https://media.blackhat.com/us-13/US-13-Prado-SSL-Gone-in-30-seconds-A-BREACH-beyond-CRIME-WP.pdf
https://community.qualys.com/blogs/securitylabs/2013/08/07/defending-against-the-breach-attack

Several mitigations have been proposed for the attack, these include the following:

1. Disable HTTP compression.
2. Separate the secrets from the user input.
3. Randomize the secrets in each client request.
4. Mask secrets (effectively randomizing by XORing with a random secret per request).
5. Protect web pages from CSRF attacks.
6. Obfuscate the length of web responses by adding random amounts of arbitrary bytes.
Comment 1 Vincent Danen 2013-08-08 19:08:11 UTC 

*** This bug has been marked as a duplicate of bug 995168 ***