CVE-2022-36079 is a medium-severity vulnerability affecting parse-community's Parse Server, an open-source backend framework that runs on Node.js and is widely used to build scalable applications. The vulnerability arises from improper handling of internal and protected fields in query constraints. Parse Server uses internal fields (prefixed with an underscore '_') and user-defined protected fields as query constraints, which are intended to be accessible only when a valid master key is provided. These fields are normally stripped from responses to unauthorized clients to prevent exposure of sensitive information. However, in affected versions prior to 4.10.14 and between 5.0.0 and 5.2.5, an attacker can enumerate these internal and protected fields by guessing query constraints and observing the server's response. This enumeration allows unauthorized actors to infer the existence and potentially the values of sensitive internal fields that should be protected, leading to exposure of sensitive information (classified under CWE-200). The vulnerability does not require authentication or user interaction, making it easier to exploit remotely. The patch introduced in versions 4.10.14 and 5.2.5 enforces the requirement of a master key to use internal and protected fields as query constraints, effectively mitigating the issue. As a temporary workaround, developers can implement a Parse Cloud Trigger 'beforeFind' to manually filter out or remove these query constraints before processing, reducing the risk of sensitive data exposure. No known exploits have been reported in the wild as of the publication date, but the vulnerability poses a risk to confidentiality of data managed by Parse Server instances running vulnerable versions.

For European organizations using Parse Server in their backend infrastructure, this vulnerability could lead to unauthorized disclosure of sensitive internal data fields, potentially exposing user data, application logic, or configuration details. This exposure could facilitate further attacks such as privilege escalation, data tampering, or targeted phishing if sensitive user information is leaked. Organizations in sectors with strict data protection regulations, such as finance, healthcare, and public services, could face compliance violations under GDPR if sensitive personal data is exposed. The impact is primarily on confidentiality, but indirectly could affect integrity if attackers leverage exposed information to craft malicious queries or escalate privileges. Since Parse Server is often used in mobile and web applications, the scope of affected systems could be broad, impacting customer-facing services and internal applications alike. The ease of exploitation without authentication increases the risk profile, especially for publicly accessible Parse Server deployments. However, the absence of known active exploits suggests that immediate widespread impact may be limited, though the vulnerability should be addressed promptly to prevent future exploitation.

Beyond applying the official patches in Parse Server versions 4.10.14 or 5.2.5, European organizations should take the following specific steps: 1) Conduct an inventory of all Parse Server instances and verify their versions to identify vulnerable deployments. 2) For legacy systems where immediate patching is not feasible, implement a 'beforeFind' Cloud Trigger to sanitize incoming queries by removing or validating query constraints that target internal or protected fields, preventing unauthorized enumeration. 3) Restrict network access to Parse Server endpoints using firewall rules or API gateways to limit exposure to trusted clients and internal networks only. 4) Enable detailed logging and monitoring of query patterns to detect abnormal enumeration attempts or suspicious query constraints targeting internal fields. 5) Review and tighten master key management policies, ensuring master keys are securely stored, rotated regularly, and not exposed in client-side code. 6) Educate development teams about the risks of exposing internal fields and enforce secure coding practices when defining protected fields and query constraints. 7) Perform penetration testing focused on query enumeration to validate the effectiveness of mitigations. These targeted actions will reduce the attack surface and help prevent sensitive data leakage through this vulnerability.