CVE-2022-41878 is a medium-severity vulnerability affecting parse-community's parse-server, an open-source backend framework widely used for building applications on Node.js infrastructure. The vulnerability arises from improper neutralization of special elements in output used by downstream components, specifically related to injection attacks (CWE-74) and prototype pollution (CWE-1321). In versions of parse-server prior to 4.10.19 and 5.3.2, the `requestKeywordDenylist` option, which is intended to block certain keywords from being processed, can be bypassed. This occurs because keywords specified in the denylist can be injected via Cloud Code Webhooks or Triggers, resulting in these keywords being saved to the database despite the denylist restrictions. The injection vector allows an attacker to manipulate backend logic or data by injecting malicious keywords that should have been blocked, potentially leading to unauthorized data modification or influencing application behavior. The vulnerability does not require authentication but does require the attacker to have access to the Cloud Code Webhooks or Triggers API endpoints. No known exploits are currently reported in the wild. The issue is resolved in parse-server versions 4.10.19 and 5.3.2. If upgrading is not feasible, mitigating controls include restricting access to the Cloud Code Webhooks API via firewall rules to trusted servers or disabling the API entirely if unused. This vulnerability highlights risks associated with insufficient input validation and improper handling of special elements in backend services that rely on dynamic code execution or webhook processing.

For European organizations using parse-server versions prior to 4.10.19, this vulnerability could lead to unauthorized injection of malicious keywords into backend processes, potentially compromising data integrity and application logic. This may result in corrupted or manipulated data stored in databases, unauthorized execution paths, or bypassing of security controls relying on keyword filtering. While the vulnerability does not directly expose confidential data or cause denial of service, the integrity impact could facilitate further attacks such as privilege escalation, data tampering, or persistent backdoors within the application environment. Organizations in sectors with high reliance on backend data integrity—such as finance, healthcare, and critical infrastructure—may face increased risks. The requirement for access to Cloud Code Webhooks or Triggers API limits the attack surface but does not eliminate risk, especially if these endpoints are exposed or insufficiently protected. The absence of known exploits reduces immediate threat but does not preclude targeted attacks, especially in environments where parse-server is widely deployed. The impact on availability is low, but integrity and potentially confidentiality could be moderately affected depending on application-specific usage of the vulnerable feature.

1. Upgrade parse-server to version 4.10.19 or later (or 5.3.2 and above) as soon as possible to apply the official fix. 2. If upgrading is not immediately possible, implement strict network-level access controls to restrict Cloud Code Webhooks and Triggers API endpoints to trusted IP addresses or internal networks only. 3. Disable the Cloud Code Webhooks API entirely if it is not used by your application to eliminate the attack vector. 4. Conduct thorough code reviews and audits of Cloud Code functions and triggers to ensure they do not rely on untrusted input or improperly sanitized keywords. 5. Implement application-layer input validation and sanitization to complement backend denylist controls, preventing injection of malicious keywords. 6. Monitor logs and alerts for unusual activity related to webhook calls or keyword injections to detect potential exploitation attempts early. 7. Educate development and operations teams about the risks of prototype pollution and injection vulnerabilities in Node.js environments to improve secure coding practices.