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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
Filtered: 90 rules found
cwe
    Impact
      Clean code attribute
        1. Server-side requests should not be vulnerable to traversing attacks

           Vulnerability
        2. JWT secret keys should not be disclosed

           Vulnerability
        3. Loop boundaries should not be vulnerable to injection attacks

           Vulnerability
        4. Connection strings should not be vulnerable to injections attacks

           Vulnerability
        5. Memory allocations should not be vulnerable to Denial of Service attacks

           Vulnerability
        6. Accessing files should not lead to filesystem oracle attacks

           Vulnerability
        7. Environment variables should not be defined from untrusted input

           Vulnerability
        8. Blocks should not be synchronized on local variables

           Bug
        9. Not specifying a timeout for regular expressions is security-sensitive

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

           Security Hotspot
        11. XML operations should not be vulnerable to injection attacks

           Vulnerability
        12. Constructing arguments of system commands from user input is security-sensitive

           Security Hotspot
        13. Applications should not create session cookies from untrusted input

           Vulnerability
        14. Reflection should not be vulnerable to injection attacks

           Vulnerability
        15. Extracting archives should not lead to zip slip vulnerabilities

           Vulnerability
        16. OS commands should not be vulnerable to argument injection attacks

           Vulnerability
        17. Types allowed to be deserialized should be restricted

           Vulnerability
        18. Deserializing objects without performing data validation is security-sensitive

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

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

           Security Hotspot
        21. JWT should be signed and verified with strong cipher algorithms

           Vulnerability
        22. Cipher algorithms should be robust

           Vulnerability
        23. Encryption algorithms should be used with secure mode and padding scheme

           Vulnerability
        24. Insecure temporary file creation methods should not be used

           Vulnerability
        25. Using publicly writable directories is security-sensitive

           Security Hotspot
        26. Passwords should not be stored in plaintext or with a fast hashing algorithm

           Vulnerability
        27. Dynamic code execution should not be vulnerable to injection attacks

           Vulnerability
        28. Using clear-text protocols is security-sensitive

           Security Hotspot
        29. NoSQL operations should not be vulnerable to injection attacks

           Vulnerability
        30. HTTP request redirections should not be open to forging attacks

           Vulnerability
        31. Logging should not be vulnerable to injection attacks

           Vulnerability
        32. Server-side requests should not be vulnerable to forging attacks

           Vulnerability
        33. Deserialization should not be vulnerable to injection attacks

           Vulnerability
        34. Endpoints should not be vulnerable to reflected cross-site scripting (XSS) attacks

           Vulnerability
        35. Having a permissive Cross-Origin Resource Sharing policy is security-sensitive

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

           Security Hotspot
        37. Server certificates should be verified during SSL/TLS connections

           Vulnerability
        38. Using weak hashing algorithms is security-sensitive

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

           Security Hotspot
        40. Disabling CSRF protections is security-sensitive

           Security Hotspot
        41. Unread "private" fields should be removed

           Code Smell
        42. LDAP connections should be authenticated

           Vulnerability
        43. Cryptographic keys should be robust

           Vulnerability
        44. Weak SSL/TLS protocols should not be used

           Vulnerability
        45. Secure random number generators should not output predictable values

           Vulnerability
        46. Searching OS commands in PATH is security-sensitive

           Security Hotspot
        47. Empty nullable value should not be accessed

           Bug
        48. Database queries should not be vulnerable to injection attacks

           Vulnerability
        49. Creating cookies without the "HttpOnly" flag is security-sensitive

           Security Hotspot
        50. Cipher Block Chaining IVs should be unpredictable

           Vulnerability
        51. Classes should "Dispose" of members from the classes' own "Dispose" methods

           Bug
        52. Classes with "IDisposable" members should implement "IDisposable"

           Bug
        53. "IDisposables" should be disposed

           Bug
        54. XML parsers should not be vulnerable to XXE attacks

           Vulnerability
        55. Multiline blocks should be enclosed in curly braces

           Code Smell
        56. Regular expressions should not be vulnerable to Denial of Service attacks

           Vulnerability
        57. Setting loose file permissions is security-sensitive

           Security Hotspot
        58. Boolean expressions should not be gratuitous

           Code Smell
        59. Conditionally executed code should be reachable

           Bug
        60. Generic exceptions should not be ignored

           Code Smell
        61. Blocks should be synchronized on read-only fields

           Bug
        62. Mutable fields should not be "public static"

           Code Smell
        63. Null pointers should not be dereferenced

           Bug
        64. Using non-standard cryptographic algorithms is security-sensitive

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

           Security Hotspot
        66. "ToString()" method should not return null

           Bug
        67. Locks should be released on all paths

           Bug
        68. "Exception" should not be caught

           Code Smell
        69. Results of integer division should not be assigned to floating point variables

           Bug
        70. A secure password should be used when connecting to a database

           Vulnerability
        71. Creating cookies without the "secure" flag is security-sensitive

           Security Hotspot
        72. XPath expressions should not be vulnerable to injection attacks

           Vulnerability
        73. I/O function calls should not be vulnerable to path injection attacks

           Vulnerability
        74. LDAP queries should not be vulnerable to injection attacks

           Vulnerability
        75. Formatting SQL queries is security-sensitive

           Security Hotspot
        76. OS commands should not be vulnerable to command injection attacks

           Vulnerability
        77. Hard-coded credentials are security-sensitive

           Security Hotspot
        78. Password hashing functions should use an unpredictable salt

           Vulnerability
        79. Invalid casts should be avoided

           Code Smell
        80. Unused assignments should be removed

           Code Smell
        81. "==" should not be used when "Equals" is overridden

           Code Smell
        82. NullReferenceException should not be caught

           Code Smell
        83. "switch/Select" statements should contain a "default/Case Else" clauses

           Code Smell
        84. "Equals(Object)" and "GetHashCode()" should be overridden in pairs

           Bug
        85. Exit methods should not be called

           Code Smell
        86. Track uses of "TODO" tags

           Code Smell
        87. Track uses of "FIXME" tags

           Code Smell
        88. Assignments should not be made from within sub-expressions

           Code Smell
        89. General or reserved exceptions should never be thrown

           Code Smell
        90. Fields should not have public accessibility

           Code Smell

        Using clear-text protocols is security-sensitive

        intentionality - complete
        security
        Security Hotspot
        • cwe

        Clear-text protocols such as ftp, telnet, or http lack encryption of transported data, as well as the capability to build an authenticated connection. It means that an attacker able to sniff traffic from the network can read, modify, or corrupt the transported content. These protocols are not secure as they expose applications to an extensive range of risks:

        • sensitive data exposure
        • traffic redirected to a malicious endpoint
        • malware-infected software update or installer
        • execution of client-side code
        • corruption of critical information

        Even in the context of isolated networks like offline environments or segmented cloud environments, the insider threat exists. Thus, attacks involving communications being sniffed or tampered with can still happen.

        For example, attackers could successfully compromise prior security layers by:

        • bypassing isolation mechanisms
        • compromising a component of the network
        • getting the credentials of an internal IAM account (either from a service account or an actual person)

        In such cases, encrypting communications would decrease the chances of attackers to successfully leak data or steal credentials from other network components. By layering various security practices (segmentation and encryption, for example), the application will follow the defense-in-depth principle.

        Note that using the http protocol is being deprecated by major web browsers.

        In the past, it has led to the following vulnerabilities:

        • CVE-2019-6169
        • CVE-2019-12327
        • CVE-2019-11065

        Ask Yourself Whether

        • Application data needs to be protected against falsifications or leaks when transiting over the network.
        • Application data transits over an untrusted network.
        • Compliance rules require the service to encrypt data in transit.
        • Your application renders web pages with a relaxed mixed content policy.
        • OS-level protections against clear-text traffic are deactivated.

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

        Recommended Secure Coding Practices

        • Make application data transit over a secure, authenticated and encrypted protocol like TLS or SSH. Here are a few alternatives to the most common clear-text protocols:
          • Use ssh as an alternative to telnet.
          • Use sftp, scp, or ftps instead of ftp.
          • Use https instead of http.
          • Use SMTP over SSL/TLS or SMTP with STARTTLS instead of clear-text SMTP.
        • Enable encryption of cloud components communications whenever it is possible.
        • Configure your application to block mixed content when rendering web pages.
        • If available, enforce OS-level deactivation of all clear-text traffic.

        It is recommended to secure all transport channels, even on local networks, as it can take a single non-secure connection to compromise an entire application or system.

        Sensitive Code Example

        var urlHttp = "http://example.com";                 // Noncompliant
        var urlFtp = "ftp://anonymous@example.com";         // Noncompliant
        var urlTelnet = "telnet://anonymous@example.com";   // Noncompliant
        
        using var smtp = new SmtpClient("host", 25); // Noncompliant, EnableSsl is not set
        using var telnet = new MyTelnet.Client("host", port); // Noncompliant, rule raises Security Hotspot on any member containing "Telnet"
        

        Compliant Solution

        var urlHttps = "https://example.com";
        var urlSftp = "sftp://anonymous@example.com";
        var urlSsh = "ssh://anonymous@example.com";
        
        using var smtp = new SmtpClient("host", 25) { EnableSsl = true };
        using var ssh = new MySsh.Client("host", port);
        

        Exceptions

        No issue is reported for the following cases because they are not considered sensitive:

        • Insecure protocol scheme followed by loopback addresses like 127.0.0.1 or localhost.

        See

        Documentation

        • AWS Documentation - Listeners for your Application Load Balancers
        • AWS Documentation - Stream Encryption

        Articles & blog posts

        • Google - Moving towards more secure web
        • Mozilla - Deprecating non secure http

        Standards

        • OWASP - Top 10 2017 Category A3 - Sensitive Data Exposure
        • OWASP - Top 10 2021 Category A2 - Cryptographic Failures
        • CWE - CWE-200 - Exposure of Sensitive Information to an Unauthorized Actor
        • CWE - CWE-319 - Cleartext Transmission of Sensitive Information
        • STIG Viewer - Application Security and Development: V-222397 - The application must implement cryptographic mechanisms to protect the integrity of remote access sessions.
        • STIG Viewer - Application Security and Development: V-222534 - Service-Oriented Applications handling non-releasable data must authenticate endpoint devices via mutual SSL/TLS.
        • STIG Viewer - Application Security and Development: V-222562 - Applications used for non-local maintenance must implement cryptographic mechanisms to protect the integrity of maintenance and diagnostic communications.
        • STIG Viewer - Application Security and Development: V-222563 - Applications used for non-local maintenance must implement cryptographic mechanisms to protect the confidentiality of maintenance and diagnostic communications.
        • STIG Viewer - Application Security and Development: V-222577 - The application must not expose session IDs.
        • STIG Viewer - Application Security and Development: V-222596 - The application must protect the confidentiality and integrity of transmitted information.
        • STIG Viewer - Application Security and Development: V-222597 - The application must implement cryptographic mechanisms to prevent unauthorized disclosure of information and/or detect changes to information during transmission.
        • STIG Viewer - Application Security and Development: V-222598 - The application must maintain the confidentiality and integrity of information during preparation for transmission.
        • STIG Viewer - Application Security and Development: V-222599 - The application must maintain the confidentiality and integrity of information during reception.
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