The 2011 CWE/SANS Top 25 Most Dangerous Software Errors is a list of the most widespread and critical errors that can lead to serious vulnerabilities in software. They are often easy to find, and easy to exploit. They are dangerous because they will frequently allow attackers to completely take over the software, steal data, or prevent the software from working at all.

The list is the result of collaboration between the SANS Institute, MITRE, and many top software security experts in the US and Europe. It leverages experiences in the development of the SANS Top 20 attack vectors (http://www.sans.org/top20/) and MITRE’s Common Weakness Enumeration (CWE) (http://cwe.mitre.org/). MITRE maintains the CWE web site, with the support of the US Department of Homeland Security’s National Cyber Security Division, presenting detailed descriptions of the top 25 programming errors along with authoritative guidance for mitigating and avoiding them. The CWE site contains data on more than 800 programming errors, design errors, and architecture errors that can lead to exploitable vulnerabilities.

Rank Score ID Name
[1] 93.8 CWE-89 Improper Neutralization of Special Elements used in an SQL Command (‘SQL Injection’)
[2] 83.3 CWE-78 Improper Neutralization of Special Elements used in an OS Command (‘OS Command Injection’)
[3] 79.0 CWE-120 Buffer Copy without Checking Size of Input (‘Classic Buffer Overflow’)
[4] 77.7 CWE-79 Improper Neutralization of Input During Web Page Generation (‘Cross-site Scripting’)
[5] 76.9 CWE-306 Missing Authentication for Critical Function
[6] 76.8 CWE-862 Missing Authorization
[7] 75.0 CWE-798 Use of Hard-coded Credentials
[8] 75.0 CWE-311 Missing Encryption of Sensitive Data
[9] 74.0 CWE-434 Unrestricted Upload of File with Dangerous Type
[10] 73.8 CWE-807 Reliance on Untrusted Inputs in a Security Decision
[11] 73.1 CWE-250 Execution with Unnecessary Privileges
[12] 70.1 CWE-352 Cross-Site Request Forgery (CSRF)
[13] 69.3 CWE-22 Improper Limitation of a Pathname to a Restricted Directory (‘Path Traversal’)
[14] 68.5 CWE-494 Download of Code Without Integrity Check
[15] 67.8 CWE-863 Incorrect Authorization
[16] 66.0 CWE-829 Inclusion of Functionality from Untrusted Control Sphere
[17] 65.5 CWE-732 Incorrect Permission Assignment for Critical Resource
[18] 64.6 CWE-676 Use of Potentially Dangerous Function
[19] 64.1 CWE-327 Use of a Broken or Risky Cryptographic Algorithm
[20] 62.4 CWE-131 Incorrect Calculation of Buffer Size
[21] 61.5 CWE-307 Improper Restriction of Excessive Authentication Attempts
[22] 61.1 CWE-601 URL Redirection to Untrusted Site (‘Open Redirect’)
[23] 61.0 CWE-134 Uncontrolled Format String
[24] 60.3 CWE-190 Integer Overflow or Wraparound
[25] 59.9 CWE-759 Use of a One-Way Hash without a Salt