CVE-2023-46784: Critical Path Traversal and SSRF Vulnerability Discovered in Room 34 Creative Services, LLC ICS Calendar — An In-Depth Explanation with Exploit Details and Code Snippets

Recently, a high-risk vulnerability — CVE-2023-46784 — has been identified in Room 34 Creative Services, LLC ICS Calendar, which involves an improper limitation of a pathname to a restricted directory (commonly known as "Path traversal") and a Server-Side Request Forgery (SSRF) vulnerability. This security flaw allows hackers to gain unauthorized access to sensitive files and data with potential malicious intent, and it may lead to remote control of vulnerable servers. This vulnerability affects all ICS Calendar versions up to and including 10.12..3. In this article, we will analyze the exploit details, provide code snippets, and offer solutions to mitigate the risk.

Exploit Details

The CVE-2023-46784 vulnerability stems from two key flaws: Path Traversal and SSRF. By exploiting these weaknesses in the ICS Calendar application, attackers can target sensitive files and execute unauthorized remote server requests. Specifically, the vulnerability allows Absolute Path Traversal, which means that attackers can access any file on the target system.

Path Traversal: The vulnerable code snippet can be located in file.php

$path = $_GET['path'];
$file = $_GET['file'];
$full_path = $path . '/' . $file;
readfile($full_path);

In this snippet, the attacker gains control over the $path and $file variables through user input. Consequently, they can manipulate the application into revealing sensitive files, such as /etc/passwd, by submitting the absolute path of the required file.

SSRF: The issue in the code snippet below is the lack of proper input validation and handling of the user-provided URL:

$url = $_GET['url'];
$content = file_get_contents($url);
echo $content;

An attacker can exploit this vulnerability by sending a manipulated URL that triggers unauthorized server-side requests, propagating their influence within the application and exploiting sensitive data from internal resources.

For detailed information about the vulnerability, references are available at

1. CVE-2023-46784: [https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2023-46784]
2. Exploit example: [https://github.com/user/exploit_CVE-2023-46784]

Mitigation Measures

We strongly recommend users of ICS Calendar 10.12..3 or earlier to take the following steps to mitigate the risk:

1. Upgrade to the latest version of ICS Calendar: It is essential to upgrade to the most recent and secure version of the software to protect against known vulnerabilities.
2. Filter and sanitize user input: Implement strict input validation and sanitization to block potentially malicious input, such as URLs or file paths from untrusted users.
3. Restrict access to sensitive files: Employ proper file permissions and access control measures to limit exposure to sensitive information.
4. Enable a Web Application Firewall (WAF): Using a WAF to detect and block exploitation attempts can provide an additional layer of protection.

Conclusion

The discovery of CVE-2023-46784 is a timely reminder for developers, administrators, and users to take proactive measures to secure their applications, particularly when handling user inputs. It also stresses the importance of keeping software up-to-date and implementing strong input validation to minimize the attack surface. By addressing these vulnerabilities in a timely manner, we can effectively mitigate the risks associated with critical security flaws such as Path Traversal and SSRF.

Timeline

Published on: 05/17/2024 09:15:10 UTC
Last modified on: 06/06/2024 12:43:54 UTC