GeoServer is an open source software server written in Java that allows users to share and edit geospatial data. An arbitrary file renaming vulnerability exists in versions prior to 2.23.5 and 2.24.2 that enables an authenticated administrator with permissions to modify stores through the REST Coverage Store or Data Store API to rename arbitrary files and directories with a name that does not end in .zip. Store file uploads rename zip files to have a .zip extension if it doesnt already have one before unzipping the file. This is fine for file and url upload methods where the files will be in a specific subdirectory of the data directory but, when using the external upload method, this allows arbitrary files and directories to be renamed. Renaming GeoServer files will most likely result in a denial of service, either completely preventing GeoServer from running or effectively deleting specific resources (such as a workspace, layer or style). In some cases, renaming GeoServer files could revert to the default settings for that file which could be relatively harmless like removing contact information or have more serious consequences like allowing users to make OGC requests that the customized settings would have prevented them from making. The impact of renaming non-GeoServer files depends on the specific environment although some sort of denial of service is a likely outcome. Versions 2.23.5 and 2.24.2 contain a fix for this issue.
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.
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.