When the Kiuwan Local Analyzer uploads the scan results to the Kiuwan SAST web application (either on-premises or cloud/SaaS solution), the transmitted data consists of a ZIP archive containing several files, some of them in the XML file format. During Kiuwans server-side processing of these XML files, it resolves external XML entities, resulting in a XML external entity injection attack. An attacker with privileges to scan source code within the Code Security module is able to extract any files of the operating system with the rights of the application server user and is potentially able to gain sensitive files, such as configuration and passwords. Furthermore, this vulnerability also allows an attacker to initiate connections to internal systems, e.g. for port scans or accessing other internal functions / applications such as the Wildfly admin console of Kiuwan.
This issue affects Kiuwan SAST: <master.1808.p685.q13371
The product processes an XML document that can contain XML entities with URIs that resolve to documents outside of the intended sphere of control, causing the product to embed incorrect documents into its output.
XML documents optionally contain a Document Type Definition (DTD), which, among other features, enables the definition of XML entities. It is possible to define an entity by providing a substitution string in the form of a URI. The XML parser can access the contents of this URI and embed these contents back into the XML document for further processing. 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. Using URIs with other schemes such as http://, the attacker can force the application to make outgoing requests to servers that the attacker cannot reach directly, which can be used to bypass firewall restrictions or hide the source of attacks such as port scanning. 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.