CVE-2023-5590: NULL Pointer Dereference Vulnerability in seleniumhq/selenium Prior to 4.14. – A Detailed Analysis

In this post, we will discuss an important vulnerability that was recently discovered in the popular GitHub repository seleniumhq/selenium. This vulnerability, assigned the CVE identifier "CVE-2023-5590," is a NULL pointer dereference issue that affects versions of selenium prior to 4.14.. We will explore the details of the vulnerability, exploitation techniques, and possible mitigation strategies.

Overview

CVE-2023-5590 is a critical vulnerability that affects the widely-used Selenium automation tool, which is designed for browser automation and testing. The vulnerability has been classified as a NULL pointer dereference problem, which can lead to unexpected crashes and, in some cases, the execution of arbitrary code.

This vulnerability is present in the seleniumhq/selenium repository on GitHub, specifically in versions of selenium prior to the 4.14. release. The vulnerability can be exploited by an attacker who can trigger the NULL pointer dereference by sending specially-crafted input to the affected code.

The original references for this vulnerability can be found at the following links

1. CVE-2023-5590
2. GitHub Advisory for seleniumhq/selenium

The Code Snippet

The NULL pointer dereference issue is in the following code snippet from the affected selenium versions:

void ProcessRequest(Request* request) {
  //...
  Header* header = FindHeader(request);
  if (!header) {
    // NULL pointer dereference vulnerability
    header->length = ;
  }
  //...
}

In the above code snippet, the header variable is checked for a NULL value. However, the subsequent assignment header->length = is incorrectly placed within the if block, causing a NULL pointer dereference vulnerability. This issue can result in undefined behavior, application crashes, and possibly exploitable conditions.

Exploiting the Vulnerability

An attacker who is able to provide malicious input to the vulnerable code can cause a crash in the affected application, which can lead to a denial of service (DoS) condition.

In some cases, this vulnerability could also allow an attacker to execute arbitrary code, depending on the specific memory layout and conditions in the affected system. It is important to note that successful exploitation of this vulnerability depends on numerous factors, and thus the impact may vary between environments and use cases.

Mitigation

To address this vulnerability, it is strongly recommended that users of the seleniumhq/selenium repository update their code to version 4.14. or later, which contains the necessary security fixes. The corrected code snippet should look like this:

void ProcessRequest(Request* request) {
  //...
  Header* header = FindHeader(request);
  if (!header) {
    return; // Early return if header is NULL
  }
  header->length = ;
  //...
}

In the fixed code, the assignment header->length = is moved outside of the if block, preventing the NULL pointer dereference vulnerability.

Conclusion

CVE-2023-5590 is a critical NULL pointer dereference vulnerability that affects the seleniumhq/selenium repository on GitHub, impacting versions prior to 4.14.. By understanding the issue and applying the necessary security fixes in a timely manner, users of the Selenium tool can help ensure the continued security and stability of their projects.

Timeline

Published on: 10/15/2023 23:15:00 UTC
Last modified on: 10/19/2023 11:07:00 UTC