Vulnerabilities > CVE-2022-0011 - Interpretation Conflict vulnerability in Paloaltonetworks Pan-Os
Summary
PAN-OS software provides options to exclude specific websites from URL category enforcement and those websites are blocked or allowed (depending on your rules) regardless of their associated URL category. This is done by creating a custom URL category list or by using an external dynamic list (EDL) in a URL Filtering profile. When the entries in these lists have a hostname pattern that does not end with a forward slash (/) or a hostname pattern that ends with an asterisk (*), any URL that starts with the specified pattern is considered a match. Entries with a caret (^) at the end of a hostname pattern match any top level domain. This may inadvertently allow or block more URLs than intended and allowing more URLs than intended represents a security risk. For example: example.com will match example.com.website.test example.com.* will match example.com.website.test example.com.^ will match example.com.test You should take special care when using such entries in policy rules that allow traffic. Where possible, use the exact list of hostname names ending with a forward slash (/) instead of using wildcards. PAN-OS 10.1 versions earlier than PAN-OS 10.1.3; PAN-OS 10.0 versions earlier than PAN-OS 10.0.8; PAN-OS 9.1 versions earlier than PAN-OS 9.1.12; all PAN-OS 9.0 versions; PAN-OS 8.1 versions earlier than PAN-OS 8.1.21, and Prisma Access 2.2 and 2.1 versions do not allow customers to change this behavior without changing the URL category list or EDL.
Vulnerable Configurations
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.