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C#

C# static code analysis

Unique rules to find Bugs, Vulnerabilities, Security Hotspots, and Code Smells in your C# code

  • All rules 493
  • Vulnerability46
  • Bug88
  • Security Hotspot24
  • Code Smell335

  • Quick Fix 61
 
Tags
    Impact
      Clean code attribute
        1. Using unsafe code blocks is security-sensitive

           Security Hotspot
        2. Not specifying a timeout for regular expressions is security-sensitive

           Security Hotspot
        3. Hard-coded secrets are security-sensitive

           Security Hotspot
        4. Constructing arguments of system commands from user input is security-sensitive

           Security Hotspot
        5. Deserializing objects without performing data validation is security-sensitive

           Security Hotspot
        6. Disabling ASP.NET "Request Validation" feature is security-sensitive

           Security Hotspot
        7. Allowing requests with excessive content length is security-sensitive

           Security Hotspot
        8. Using publicly writable directories is security-sensitive

           Security Hotspot
        9. Using clear-text protocols is security-sensitive

           Security Hotspot
        10. Having a permissive Cross-Origin Resource Sharing policy is security-sensitive

           Security Hotspot
        11. Expanding archive files without controlling resource consumption is security-sensitive

           Security Hotspot
        12. Configuring loggers is security-sensitive

           Security Hotspot
        13. Using weak hashing algorithms is security-sensitive

           Security Hotspot
        14. Delivering code in production with debug features activated is security-sensitive

           Security Hotspot
        15. Disabling CSRF protections is security-sensitive

           Security Hotspot
        16. Searching OS commands in PATH is security-sensitive

           Security Hotspot
        17. Creating cookies without the "HttpOnly" flag is security-sensitive

           Security Hotspot
        18. Setting loose file permissions is security-sensitive

           Security Hotspot
        19. Using non-standard cryptographic algorithms is security-sensitive

           Security Hotspot
        20. Using pseudorandom number generators (PRNGs) is security-sensitive

           Security Hotspot
        21. Creating cookies without the "secure" flag is security-sensitive

           Security Hotspot
        22. Formatting SQL queries is security-sensitive

           Security Hotspot
        23. Hard-coded credentials are security-sensitive

           Security Hotspot
        24. Using hardcoded IP addresses is security-sensitive

           Security Hotspot

        Creating cookies without the "HttpOnly" flag is security-sensitive

        intentionality - complete
        security
        Security Hotspot
        • cwe
        • privacy

        When a cookie is configured with the HttpOnly attribute set to true, the browser guaranties that no client-side script will be able to read it. In most cases, when a cookie is created, the default value of HttpOnly is false and it’s up to the developer to decide whether or not the content of the cookie can be read by the client-side script. As a majority of Cross-Site Scripting (XSS) attacks target the theft of session-cookies, the HttpOnly attribute can help to reduce their impact as it won’t be possible to exploit the XSS vulnerability to steal session-cookies.

        Ask Yourself Whether

        • the cookie is sensitive, used to authenticate the user, for instance a session-cookie
        • the HttpOnly attribute offer an additional protection (not the case for an XSRF-TOKEN cookie / CSRF token for example)

        There is a risk if you answered yes to any of those questions.

        Recommended Secure Coding Practices

        • By default the HttpOnly flag should be set to true for most of the cookies and it’s mandatory for session / sensitive-security cookies.

        Sensitive Code Example

        When the HttpCookie.HttpOnly property is set to false then the cookie can be accessed by client side code:

        HttpCookie myCookie = new HttpCookie("Sensitive cookie");
        myCookie.HttpOnly = false; // Sensitive: this cookie is created with the httponly flag set to false and so it can be stolen easily in case of XSS vulnerability
        

        The default value of HttpOnly flag is false, unless overwritten by an application’s configuration file:

        HttpCookie myCookie = new HttpCookie("Sensitive cookie");
        // Sensitive: this cookie is created without the httponly flag  (by default set to false) and so it can be stolen easily in case of XSS vulnerability
        

        Compliant Solution

        Set the HttpCookie.HttpOnly property to true:

        HttpCookie myCookie = new HttpCookie("Sensitive cookie");
        myCookie.HttpOnly = true; // Compliant: the sensitive cookie is protected against theft thanks to the HttpOnly property set to true (HttpOnly = true)
        

        Or change the default flag values for the whole application by editing the Web.config configuration file:

        <httpCookies httpOnlyCookies="true" requireSSL="true" />
        
        • the requireSSL attribute corresponds programmatically to the Secure field.
        • the httpOnlyCookies attribute corresponds programmatically to the httpOnly field.

        See

        • OWASP - Top 10 2021 Category A5 - Security Misconfiguration
        • OWASP HttpOnly
        • OWASP - Top 10 2017 Category A7 - Cross-Site Scripting (XSS)
        • CWE - CWE-1004 - Sensitive Cookie Without 'HttpOnly' Flag
        • Derived from FindSecBugs rule HTTPONLY_COOKIE
        • STIG Viewer - Application Security and Development: V-222575 - The application must set the HTTPOnly flag on session cookies.
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          Available Since
          9.1
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          Developer Edition
          Available Since
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