CVE-2026-74881 in openssl_encrypt
Summary
by MITRE • 08/17/2026
openssl_encrypt versions before 1.4.0 configure CORS with allow_origins set to wildcard and allow_credentials enabled to true. Attackers can create malicious websites that make authenticated cross-origin requests to the API on behalf of any user who visits them.
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Analysis
by VulDB Data Team • 08/17/2026
The vulnerability in openssl_encrypt prior to version 1.4.0 stems from a misconfiguration of Cross-Origin Resource Sharing (CORS) policies, specifically involving an overly permissive origin allowance combined with credential transmission settings. In web security architecture, CORS is the mechanism that allows or restricts resources on a web page from being requested by another domain outside the domain from which the first resource was served. The specific flaw here involves setting the allow_origins directive to a wildcard value, typically represented as an asterisk (*), while simultaneously enabling the allow_credentials flag set to true. This combination creates a critical security gap because it instructs web browsers that any origin is permitted to access the API resources and that such requests may include user credentials like cookies, HTTP authentication headers, or client-side SSL certificates.
This configuration effectively neutralizes the Same-Origin Policy protections intended to prevent malicious sites from reading sensitive data belonging to users authenticated on a different domain. When an attacker constructs a malicious website designed to exploit this vulnerability, they can embed scripts that initiate cross-origin requests to the vulnerable API endpoint. Because the server explicitly permits all origins and allows credentials to be sent with these requests, the browser will attach the victim's session cookies or authentication tokens to the request made by the attacker’s script. Consequently, the malicious website acts as a proxy for any user who visits it while logged into the target application, allowing the attacker to perform actions on behalf of that user without their knowledge or consent.
The operational impact of this vulnerability is severe and aligns with several well-known security weaknesses defined in industry standards. It directly corresponds to CWE-942, which describes Permissive Cross-domain Policy with Untrusted Data, as the server trusts all domains when handling sensitive data. Furthermore, from an offensive perspective, this flaw facilitates Cross-Site Request Forgery (CSRF) attacks where the attacker leverages the victim’s authenticated session to execute state-changing requests such as fund transfers, profile modifications, or administrative actions. This scenario is also closely related to CWE-352, which covers the Cross-Site Request Forgery vulnerability itself, and can be mapped to MITRE ATT&CK techniques involving browser-based attacks where an adversary uses a user’s credentials to interact with web applications.
To mitigate this risk, developers must immediately update openssl_encrypt to version 1.4.0 or later if such an update resolves the configuration issue, although the primary fix lies in correcting the CORS policy implementation regardless of the library version. The allow_origins setting should never be set to a wildcard when credentials are enabled. Instead, it should explicitly list only the trusted domains that require access to the API resources. If dynamic origin validation is required, the server must implement logic to check the Origin header against an allowed whitelist and reflect back only those origins that match. Additionally, ensuring that allow_credentials remains true while restricting origins significantly reduces the attack surface by preventing unauthorized third-party sites from leveraging user sessions. Regular security audits of web application configurations are essential to prevent such misconfigurations in production environments.