CVE-2024-27185: Addressing the Pagination Class Arbitrary Parameters Issue and Cache Poisoning Exploits in Web Applications

CVE-2024-27185 is a vulnerability that resides in the pagination class, causing web applications to inadvertently include arbitrary parameters in links. This opens the door for attackers to exploit cache poisoning and compromise user data. In this exhaustive guide, we will delve into the details of this vulnerability, its potential impact, and the steps that developers should take to address the situation.

Technical Analysis

The vulnerability in question, CVE-2024-27185, affects the pagination class, which is commonly used in web applications to streamline the process of displaying and navigating numerous pages of content. It has been discovered that this class includes arbitrary parameters when generating and constructing links, leading to potential cache poisoning attacks.

Cache poisoning is a type of security exploit in which an attacker manipulates a cache in a way that distributes malicious content to other users. In the context of the pagination class, attackers have the ability to manipulate links containing arbitrary and potentially malicious parameters. When these links are clicked on, the cache gets poisoned with the attacker's malicious payload, eventually delivering it to other unsuspecting users.

To better understand how this vulnerability can be exploited, let's take a look at a simple code snippet that demonstrates how the pagination class incorrectly generates links with arbitrary parameters:

class Pagination:
     def __init__(self, page, per_page, total_items):
          self.page = page
          self.per_page = per_page
          self.total_items = total_items
     
     def generate_links(self, base_url, **kwargs):
          links = []
          for page_num in range(1, self.total_pages + 1):
               link_params = {"page": page_num, **kwargs}
               link = base_url + "?" + urlencode(link_params)
               links.append(link)
          return links

paginator = Pagination(1, 10, 100)
paginator.generate_links("/demo", foo="bar", malicious_param="malicious_value")

One might expect the generated links to only contain the necessary page number parameter to navigate the paginated content. However, due to the **kwargs usage, the links include any additional (and potentially malicious) parameters passed to the generate_links function.

You can find further details on the original disclosure of this vulnerability in this advisory: CVE-2024-27185 Advisory

Mitigation

There are several steps developers can take to minimize the impact of this vulnerability.

1. Update the pagination class: Modify the generate_links method to only accept and include necessary parameters in the generated URLs. This may involve defining a list of allowed parameters and filtering out any unexpected or malicious entries.

class Pagination:
     # ...
     
     def generate_links(self, base_url, **kwargs):
          allowed_params = ["param1", "param2"]  # Define allowed parameters
          sanitized_kwargs = {k: v for k, v in kwargs.items() if k in allowed_params}
          links = []
          for page_num in range(1, self.total_pages + 1):
               link_params = {"page": page_num, **sanitized_kwargs}
               link = base_url + "?" + urlencode(link_params)
               links.append(link)
          return links

2. Validate user input: Make sure that any user-supplied data going through the pagination class is properly sanitized and validated. This will help prevent the introduction of malicious parameters and protect your application from cache poisoning attacks.

3. Employ strong caching and security techniques: Enable and configure cache-control headers, ensuring that your application follows best practices for caching and security. This might include setting proper 'Cache-Control', 'Pragma', and 'Expires' headers to instruct browsers and caches on how to store and serve your content.

Conclusion

CVE-2024-27185 is a critical vulnerability affecting the pagination class in web applications. Developers should be proactive in mitigating the risks associated with this flaw, as it could enable potentially devastating cache poisoning attacks. With a combination of regular updates, proper code review, and adherence to security best practices, developers can significantly reduce the impact of this vulnerability and protect their users from potential exploitation.

Timeline

Published on: 08/20/2024 16:15:10 UTC
Last modified on: 09/22/2024 05:15:11 UTC