CVE-2026-73235
Description
A flaw was found in FreeCAD. A remote attacker could exploit a vulnerability in the application's XML parser when opening a specially crafted .FCStd archive. The parser, which processes the Document.xml file, does not properly restrict the resolution of external entities or the loading of external Document Type Definitions (DTDs). This allows an attacker to read local files on the system or initiate server-side requests, potentially leading to sensitive information disclosure.
Statement
Red Hat Product Security has determined that this vulnerability does not affect any currently supported Red Hat product. This assessment may evolve based on further analysis and discovery. For more information about this vulnerability and the products it affects, please see the linked references.
Understanding the Weakness (CWE)
Confidentiality
Technical Impact: Read Application Data; Read Files or Directories
If the attacker is able to include a crafted DTD and a default entity resolver is enabled, the attacker may be able to access arbitrary files on the system. By submitting an XML file that defines an external entity with a file:// URI, an attacker can cause the processing application to read the contents of a local file. For example, a URI such as "file:///c:/winnt/win.ini" designates (in Windows) the file C:\Winnt\win.ini, or file:///etc/passwd designates the password file in Unix-based systems. Once the content of the URI is read, it is fed back into the application that is processing the XML. This application may echo back the data (e.g., in an error message), thereby exposing the file contents.
Integrity
Technical Impact: Bypass Protection Mechanism
An attacker may supply a crafted DTD using URIs with schemes such as http://, forcing the application to make outgoing HTTP requests to servers that the attacker cannot reach directly, which can be used to bypass firewall restrictions; hide the source of attacks such as port scanning; or otherwise leverage the server's trust relationship with other entities.
Availability
Technical Impact: DoS: Resource Consumption (CPU); DoS: Resource Consumption (Memory)
The product could consume excessive CPU cycles or memory using a URI that points to a large file, or a device that always returns data such as /dev/random. Alternately, the URI could reference a file that contains many nested or recursive entity references to further slow down parsing.
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