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Code injection

ID: py/code-injection
Kind: path-problem
Security severity: 9.3
Severity: error
Precision: high
Tags:
   - security
   - external/cwe/cwe-094
   - external/cwe/cwe-095
   - external/cwe/cwe-116
Query suites:
   - python-code-scanning.qls
   - python-security-extended.qls
   - python-security-and-quality.qls

Click to see the query in the CodeQL repository

Directly evaluating user input (for example, an HTTP request parameter) as code without properly sanitizing the input first allows an attacker arbitrary code execution. This can occur when user input is passed to code that interprets it as an expression to be evaluated, such as eval or exec.

Recommendation

Avoid including user input in any expression that may be dynamically evaluated. If user input must be included, use context-specific escaping before including it. It is important that the correct escaping is used for the type of evaluation that will occur.

Example

The following example shows two functions setting a name from a request. The first function uses exec to execute the