IPython (Interactive Python) is a command shell for interactive computing in multiple programming languages, originally developed for the Python programming language. Versions prior to 8.1.0 are subject to a command injection vulnerability with very specific prerequisites. This vulnerability requires that the function IPython.utils.terminal.set_term_title be called on Windows in a Python environment where ctypes is not available. The dependency on ctypes in IPython.utils._process_win32 prevents the vulnerable code from ever being reached in the ipython binary. However, as a library that could be used by another tool set_term_title could be called and hence introduce a vulnerability. Should an attacker get untrusted input to an instance of this function they would be able to inject shell commands as current process and limited to the scope of the current process. Users of ipython as a library are advised to upgrade. Users unable to upgrade should ensure that any calls to the IPython.utils.terminal.set_term_title function are done with trusted or filtered input.
The product receives input or data, but it does not validate or incorrectly validates that the input has the properties that are required to process the data safely and correctly.
| Name | Vendor | Start Version | End Version |
|---|---|---|---|
| Ipython | Ipython | * | 8.10.0 (excluding) |
| Ipython | Ubuntu | bionic | * |
| Ipython | Ubuntu | kinetic | * |
| Ipython | Ubuntu | lunar | * |
| Ipython | Ubuntu | mantic | * |
| Ipython | Ubuntu | trusty | * |
| Ipython | Ubuntu | trusty/esm | * |
| Ipython | Ubuntu | xenial | * |
Input validation is a frequently-used technique for checking potentially dangerous inputs in order to ensure that the inputs are safe for processing within the code, or when communicating with other components. When software does not validate input properly, an attacker is able to craft the input in a form that is not expected by the rest of the application. This will lead to parts of the system receiving unintended input, which may result in altered control flow, arbitrary control of a resource, or arbitrary code execution. Input validation is not the only technique for processing input, however. Other techniques attempt to transform potentially-dangerous input into something safe, such as filtering (CWE-790) - which attempts to remove dangerous inputs - or encoding/escaping (CWE-116), which attempts to ensure that the input is not misinterpreted when it is included in output to another component. Other techniques exist as well (see CWE-138 for more examples.) Input validation can be applied to:
Data can be simple or structured. Structured data can be composed of many nested layers, composed of combinations of metadata and raw data, with other simple or structured data. Many properties of raw data or metadata may need to be validated upon entry into the code, such as:
Implied or derived properties of data must often be calculated or inferred by the code itself. Errors in deriving properties may be considered a contributing factor to improper input validation.
Note that “input validation” has very different meanings to different people, or within different classification schemes. Caution must be used when referencing this CWE entry or mapping to it. For example, some weaknesses might involve inadvertently giving control to an attacker over an input when they should not be able to provide an input at all, but sometimes this is referred to as input validation. Finally, it is important to emphasize that the distinctions between input validation and output escaping are often blurred, and developers must be careful to understand the difference, including how input validation is not always sufficient to prevent vulnerabilities, especially when less stringent data types must be supported, such as free-form text. Consider a SQL injection scenario in which a person’s last name is inserted into a query. The name “O’Reilly” would likely pass the validation step since it is a common last name in the English language. However, this valid name cannot be directly inserted into the database because it contains the “’” apostrophe character, which would need to be escaped or otherwise transformed. In this case, removing the apostrophe might reduce the risk of SQL injection, but it would produce incorrect behavior because the wrong name would be recorded.