CVE-2024-57177 identifies a host header injection vulnerability in the perfood/couch-auth NPM package, versions up to 0.21.2. The vulnerability arises when the application processes the host header in the email change confirmation request without proper validation or sanitization. By crafting a malicious host header, an attacker can trigger a server-side template injection (SSTI) within the package's template rendering logic. SSTI vulnerabilities allow attackers to inject and execute arbitrary code or commands on the server, or to leak sensitive server-side information. In this case, the SSTI is limited but still enables execution of some commands or data leakage. The vulnerability does not require any privileges or user interaction, making it remotely exploitable over the network. The CVSS 3.1 score of 7.3 reflects the network attack vector, low attack complexity, no privileges required, no user interaction, and impacts on confidentiality, integrity, and availability. Although no public exploits are currently known, the vulnerability's nature and ease of exploitation make it a significant threat. The CWE-1336 classification corresponds to improper neutralization of input during template processing, a common root cause for SSTI. The lack of available patches at the time of publication necessitates immediate mitigation efforts by users of the package.

For European organizations, the impact of CVE-2024-57177 can be substantial, especially for those relying on the perfood/couch-auth package in their authentication workflows. Exploitation could lead to unauthorized disclosure of sensitive user or server information, undermining confidentiality. The ability to execute limited commands threatens system integrity and could facilitate further attacks or persistence mechanisms. Availability might also be affected if the injected commands disrupt normal service operations. Organizations handling personal data under GDPR face additional regulatory risks if this vulnerability leads to data breaches. Given the package’s role in authentication, successful exploitation could compromise user accounts or enable privilege escalation. The threat is particularly relevant to European software companies, SaaS providers, and enterprises with Node.js-based backend services. The absence of known exploits provides a window for proactive defense, but the vulnerability’s characteristics demand urgent remediation to prevent potential exploitation.

To mitigate CVE-2024-57177, organizations should first check for updates or patches from the perfood/couch-auth maintainers and apply them promptly once available. In the absence of official patches, developers should implement strict validation and sanitization of the host header values before processing them in any template rendering context. Employing allowlists for acceptable host header values can reduce injection risks. Additionally, refactor the email change confirmation logic to avoid direct injection of untrusted input into templates. Use secure template engines that enforce context-aware escaping and sandboxing to limit SSTI impact. Implement runtime application self-protection (RASP) or web application firewalls (WAF) with rules to detect and block suspicious host header manipulations. Monitor application logs for unusual host header patterns or errors indicative of attempted SSTI exploitation. Conduct code reviews focusing on template rendering and input handling. Finally, educate development teams about secure coding practices related to template injection vulnerabilities.