CVE-2025-34045 is a path traversal vulnerability classified under CWE-22 affecting WeiPHP version 5.0, a framework designed for developing WeChat public account platforms. The vulnerability resides in the picUrl parameter of the /public/index.php/material/Material/_download_imgage endpoint. Due to insufficient input validation, attackers can craft POST requests that include directory traversal sequences (e.g., ../) to access files outside the intended directory scope. This flaw allows unauthenticated remote attackers to read arbitrary files on the server, including sensitive configuration files and source code, which could lead to further compromise or information leakage. The vulnerability does not require any privileges or user interaction, making it highly exploitable remotely. The CVSS 4.0 vector (AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N) reflects network attack vector, low complexity, no authentication or user interaction, and high confidentiality impact. Although no public exploit code is currently known, Shadowserver Foundation observed exploitation attempts in February 2025, indicating active reconnaissance or targeted attacks. WeiPHP is primarily used in Chinese digital ecosystems but has international deployments due to WeChat's global presence. The lack of official patches at the time of publication increases the urgency for organizations to implement compensating controls.

For European organizations, exploitation of this vulnerability could lead to unauthorized disclosure of sensitive information such as internal configuration files, credentials, and source code. This exposure can facilitate further attacks, including privilege escalation, lateral movement, or data exfiltration. Organizations relying on WeiPHP 5.0 for WeChat public account management or integration risk operational disruption and reputational damage if sensitive data is leaked. Given the unauthenticated nature of the exploit, attackers can scan and target vulnerable servers en masse, increasing the likelihood of compromise. The impact is particularly critical for sectors handling sensitive personal data or intellectual property, such as finance, healthcare, and technology. Additionally, exposure of source code could reveal other security weaknesses, compounding the risk. The vulnerability undermines confidentiality without affecting integrity or availability directly but can be a stepping stone for more severe attacks.

1. Immediately restrict access to the /public/index.php/material/Material/_download_imgage endpoint using network-level controls such as firewalls or web application firewalls (WAFs) to block suspicious requests containing directory traversal patterns. 2. Implement strict input validation and sanitization on the picUrl parameter to reject any input containing traversal sequences (e.g., ../) or disallowed characters. 3. Employ a whitelist approach for file paths or names that can be accessed through this endpoint, ensuring only legitimate files are retrievable. 4. Monitor web server and application logs for unusual access patterns or repeated attempts to exploit directory traversal. 5. Isolate WeiPHP instances in segmented network zones to limit potential lateral movement if compromised. 6. Engage with the vendor or community to obtain patches or updates addressing this vulnerability and apply them promptly once available. 7. Conduct security audits and penetration testing focused on file access endpoints to identify similar weaknesses. 8. Educate development teams on secure coding practices to prevent path traversal and related vulnerabilities in future releases.