Author: Ameeba

Overview

Today we are breaking down a critical vulnerability, CVE-2025-25264, which allows an unauthenticated remote attacker to exploit an overly permissive Cross-Origin Resource Sharing (CORS) policy. This vulnerability poses a significant threat to any system that has not yet applied the corresponding patch, potentially leading to serious data leakage or enabling further system compromise. It is of utmost importance that system administrators understand the risks and take action to mitigate this vulnerability.

Vulnerability Summary

CVE ID: CVE-2025-25264
Severity: Critical, CVSS score 8.8
Attack Vector: Network
Privileges Required: None
User Interaction: None
Impact: System compromise or data leakage

Affected Products

Product | Affected Versions

Vendor Product 1 | All versions prior to 3.0.1
Vendor Product 2 | All versions prior to 2.1.6

How the Exploit Works

An attacker can exploit this vulnerability by sending a cross-origin HTTP request to a vulnerable application. The overly permissive CORS policy of the affected application allows the attacker to read the responses to these cross-origin requests, potentially exposing sensitive data or enabling further attacks. Since the attack can be executed remotely, the attacker does not need to authenticate or interact with a user to successfully exploit the vulnerability.

Conceptual Example Code

The following conceptual example demonstrates how an attacker might exploit this vulnerability:

GET /sensitive/data HTTP/1.1
Host: vulnerable.example.com
Origin: attacker.example.com

In this example, the attacker sends a GET request from `attacker.example.com` to `vulnerable.example.com` for a resource that contains sensitive data. The vulnerable application’s overly permissive CORS policy allows the attacker’s domain to read the response, potentially exposing sensitive data.

Mitigation Guidance

To mitigate this vulnerability, apply the patch provided by the vendor as soon as possible. If the patch cannot be applied immediately, consider using a Web Application Firewall (WAF) or Intrusion Detection System (IDS) to detect and block exploitation attempts. Additionally, review and update the application’s CORS policy to ensure that it only allows trusted domains to read responses.

Overview

The vulnerability CVE-2025-40916 is a critical cybersecurity issue that affects the Mojolicious::Plugin::CaptchaPNG version 1.05 for Perl. This vulnerability is primarily related to the weak random number source used for generating the captcha. The importance of this issue is underscored by the potential for system compromise or data leakage, which can have severe ramifications for any system reliant on this software plugin. It is therefore crucial for developers and system administrators to understand the nature of this vulnerability and to implement necessary mitigation strategies to secure their systems.

Vulnerability Summary

CVE ID: CVE-2025-40916
Severity: Critical (CVSS: 9.1)
Attack Vector: Network
Privileges Required: None
User Interaction: Required
Impact: System compromise and potential data leakage

Affected Products

Product | Affected Versions

Mojolicious::Plugin::CaptchaPNG | 1.05

How the Exploit Works

The CVE-2025-40916 exploit hinges on the Mojolicious::Plugin::CaptchaPNG’s use of a weak random number source, specifically the built-in rand() function. This function is responsible for generating the captcha text and image noise. However, its inherent insecurity lies in its predictability, which can be exploited by an attacker to bypass the captcha verification process. With successful prediction and bypass, an attacker could potentially gain unauthorized access to system resources and data.

Conceptual Example Code

The following is a conceptual representation of how the vulnerability might be exploited. In this case, an attacker might use a sequence of known or predicted random numbers to bypass the captcha:

use Mojolicious::Lite;
use Mojolicious::Plugin::CaptchaPNG;
my $c = captcha png => {
width => 300,
height => 100,
len => 6,
lines => 10,
particles => 200,
};
# Here, the attacker predicts the next number in the sequence
my $predicted_captcha = predict_next_rand($c->random);
# The attacker then sends this predicted captcha as a response
send_captcha_response($predicted_captcha);
# If the prediction is correct, captcha verification is bypassed
if (verify_captcha($predicted_captcha)) {
# The attacker gains unauthorized access
access_system_resources();
}

Keep in mind that this is a conceptual example and actual implementation may vary based on the specific context and the attacker’s knowledge of the system’s random number generation process.