Vulnerabilities > CVE-2019-19589 - Interpretation Conflict vulnerability in Wp-Pdf PDF Embedder 4.4
Summary
The Lever PDF Embedder plugin 4.4 for WordPress does not block the distribution of polyglot PDF documents that are valid JAR archives. Note: It has been argued that "The vulnerability reported in PDF Embedder Plugin is not valid as the plugin itself doesn't control or manage the file upload process. It only serves the uploaded PDF files and the responsibility of uploading PDF file remains with the Site owner of Wordpress installation, the upload of PDF file is managed by Wordpress core and not by PDF Embedder Plugin. Control & block of polyglot file is required to be taken care at the time of upload, not on showing the file. Moreover, the reference mentions retrieving the files from the browser cache and manually renaming it to jar for executing the file. That refers to a two step non-connected steps which has nothing to do with PDF Embedder.
Vulnerable Configurations
| Part | Description | Count |
|---|---|---|
| Application | 1 |
Common Weakness Enumeration (CWE)
Common Attack Pattern Enumeration and Classification (CAPEC)
- HTTP Request Splitting HTTP Request Splitting (also known as HTTP Request Smuggling) is an attack pattern where an attacker attempts to insert additional HTTP requests in the body of the original (enveloping) HTTP request in such a way that the browser interprets it as one request but the web server interprets it as two. There are several ways to perform HTTP request splitting attacks. One way is to include double Content-Length headers in the request to exploit the fact that the devices parsing the request may each use a different header. Another way is to submit an HTTP request with a "Transfer Encoding: chunked" in the request header set with setRequestHeader to allow a payload in the HTTP Request that can be considered as another HTTP Request by a subsequent parsing entity. A third way is to use the "Double CR in an HTTP header" technique. There are also a few less general techniques targeting specific parsing vulnerabilities in certain web servers.
- HTTP Response Smuggling An attacker injects content into a server response that is interpreted differently by intermediaries than it is by the target browser. To do this, it takes advantage of inconsistent or incorrect interpretations of the HTTP protocol by various applications. For example, it might use different block terminating characters (CR or LF alone), adding duplicate header fields that browsers interpret as belonging to separate responses, or other techniques. Consequences of this attack can include response-splitting, cross-site scripting, apparent defacement of targeted sites, cache poisoning, or similar actions.
- HTTP Request Smuggling HTTP Request Smuggling results from the discrepancies in parsing HTTP requests between HTTP entities such as web caching proxies or application firewalls. Entities such as web servers, web caching proxies, application firewalls or simple proxies often parse HTTP requests in slightly different ways. Under specific situations where there are two or more such entities in the path of the HTTP request, a specially crafted request is seen by two attacked entities as two different sets of requests. This allows certain requests to be smuggled through to a second entity without the first one realizing it.