A03:2021 – Injection
|CWEs Mapped||Max Incidence Rate||Avg Incidence Rate||Avg Weighted Exploit||Avg Weighted Impact||Max Coverage||Avg Coverage||Total Occurrences||Total CVEs|
Injection slides down to the third position. 94% of the applications were tested for some form of injection with a max incidence rate of 19%, an average incidence rate of 3%, and 274k occurrences. Notable Common Weakness Enumerations (CWEs) included are CWE-79: Cross-site Scripting, CWE-89: SQL Injection, and CWE-73: External Control of File Name or Path.
An application is vulnerable to attack when:
User-supplied data is not validated, filtered, or sanitized by the application.
Dynamic queries or non-parameterized calls without context-aware escaping are used directly in the interpreter.
Hostile data is used within object-relational mapping (ORM) search parameters to extract additional, sensitive records.
Hostile data is directly used or concatenated. The SQL or command contains the structure and malicious data in dynamic queries, commands, or stored procedures.
Some of the more common injections are SQL, NoSQL, OS command, Object Relational Mapping (ORM), LDAP, and Expression Language (EL) or Object Graph Navigation Library (OGNL) injection. The concept is identical among all interpreters. Source code review is the best method of detecting if applications are vulnerable to injections. Automated testing of all parameters, headers, URL, cookies, JSON, SOAP, and XML data inputs is strongly encouraged. Organizations can include static (SAST), dynamic (DAST), and interactive (IAST) application security testing tools into the CI/CD pipeline to identify introduced injection flaws before production deployment.
How to Prevent
Preventing injection requires keeping data separate from commands and queries:
The preferred option is to use a safe API, which avoids using the interpreter entirely, provides a parameterized interface, or migrates to Object Relational Mapping Tools (ORMs).
Note: Even when parameterized, stored procedures can still introduce SQL injection if PL/SQL or T-SQL concatenates queries and data or executes hostile data with EXECUTE IMMEDIATE or exec().
Use positive server-side input validation. This is not a complete defense as many applications require special characters, such as text areas or APIs for mobile applications.
For any residual dynamic queries, escape special characters using the specific escape syntax for that interpreter.
Note: SQL structures such as table names, column names, and so on cannot be escaped, and thus user-supplied structure names are dangerous. This is a common issue in report-writing software.
Use LIMIT and other SQL controls within queries to prevent mass disclosure of records in case of SQL injection.
Example Attack Scenarios
Scenario #1: An application uses untrusted data in the construction of the following vulnerable SQL call:
String query = "SELECT \* FROM accounts WHERE custID='" + request.getParameter("id") + "'";
Scenario #2: Similarly, an application’s blind trust in frameworks may result in queries that are still vulnerable, (e.g., Hibernate Query Language (HQL)):
Query HQLQuery = session.createQuery("FROM accounts WHERE custID='" + request.getParameter("id") + "'");
In both cases, the attacker modifies the ‘id’ parameter value in their browser to send: ' UNION SLEEP(10);--. For example:
http://example.com/app/accountView?id=' UNION SELECT SLEEP(10);--
This changes the meaning of both queries to return all the records from the accounts table. More dangerous attacks could modify or delete data or even invoke stored procedures.
OWASP Testing Guide: SQL Injection, Command Injection, and ORM Injection
List of Mapped CWEs
CWE-20 Improper Input Validation
CWE-74 Improper Neutralization of Special Elements in Output Used by a Downstream Component ('Injection')
CWE-75 Failure to Sanitize Special Elements into a Different Plane (Special Element Injection)
CWE-77 Improper Neutralization of Special Elements used in a Command ('Command Injection')
CWE-78 Improper Neutralization of Special Elements used in an OS Command ('OS Command Injection')
CWE-79 Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
CWE-80 Improper Neutralization of Script-Related HTML Tags in a Web Page (Basic XSS)
CWE-83 Improper Neutralization of Script in Attributes in a Web Page
CWE-87 Improper Neutralization of Alternate XSS Syntax
CWE-88 Improper Neutralization of Argument Delimiters in a Command ('Argument Injection')
CWE-89 Improper Neutralization of Special Elements used in an SQL Command ('SQL Injection')
CWE-90 Improper Neutralization of Special Elements used in an LDAP Query ('LDAP Injection')
CWE-91 XML Injection (aka Blind XPath Injection)
CWE-93 Improper Neutralization of CRLF Sequences ('CRLF Injection')
CWE-94 Improper Control of Generation of Code ('Code Injection')
CWE-95 Improper Neutralization of Directives in Dynamically Evaluated Code ('Eval Injection')
CWE-96 Improper Neutralization of Directives in Statically Saved Code ('Static Code Injection')
CWE-97 Improper Neutralization of Server-Side Includes (SSI) Within a Web Page
CWE-98 Improper Control of Filename for Include/Require Statement in PHP Program ('PHP Remote File Inclusion')
CWE-99 Improper Control of Resource Identifiers ('Resource Injection')
CWE-100 Deprecated: Was catch-all for input validation issues
CWE-113 Improper Neutralization of CRLF Sequences in HTTP Headers ('HTTP Response Splitting')
CWE-116 Improper Encoding or Escaping of Output
CWE-138 Improper Neutralization of Special Elements
CWE-184 Incomplete List of Disallowed Inputs
CWE-470 Use of Externally-Controlled Input to Select Classes or Code ('Unsafe Reflection')
CWE-471 Modification of Assumed-Immutable Data (MAID)
CWE-564 SQL Injection: Hibernate
CWE-610 Externally Controlled Reference to a Resource in Another Sphere
CWE-643 Improper Neutralization of Data within XPath Expressions ('XPath Injection')
CWE-644 Improper Neutralization of HTTP Headers for Scripting Syntax
CWE-652 Improper Neutralization of Data within XQuery Expressions ('XQuery Injection')
CWE-917 Improper Neutralization of Special Elements used in an Expression Language Statement ('Expression Language Injection')