CVE-2022-27562 is a medium-severity vulnerability identified in HCL Software's HCL Domino Volt product, specifically affecting versions 1.0 through 1.0.5. The vulnerability stems from an unsafe default file type filter policy that permits the upload of .html files without adequate restrictions. This weakness corresponds to CWE-434: Unrestricted Upload of File with Dangerous Type. By allowing .html files to be uploaded, the system inadvertently enables the execution of potentially unsafe JavaScript code embedded within these files in deployed applications. This can lead to client-side script execution in the context of the application, which may be exploited to conduct cross-site scripting (XSS) attacks or other malicious activities that compromise the integrity and confidentiality of user data. The CVSS 3.1 base score is 4.6 (medium), with the vector indicating network attack vector (AV:N), low attack complexity (AC:L), requiring privileges (PR:L), user interaction (UI:R), unchanged scope (S:U), and low impact on confidentiality and integrity (C:L, I:L), with no impact on availability (A:N). No known exploits are currently reported in the wild, and no patches have been linked yet. The vulnerability requires an authenticated user to upload a malicious .html file and for a victim to interact with the application to trigger the unsafe JavaScript execution. This vulnerability primarily impacts the web application layer of HCL Domino Volt, which is used for rapid application development and deployment within enterprise environments. The unsafe file upload policy could be exploited to inject malicious scripts that affect users interacting with the deployed applications, potentially leading to data leakage or manipulation of application behavior.

For European organizations using HCL Domino Volt, this vulnerability poses a risk primarily to the confidentiality and integrity of data handled within deployed applications. Since the vulnerability allows execution of unsafe JavaScript via uploaded .html files, attackers with authenticated access could upload malicious files that, when accessed by other users, execute scripts capable of stealing session tokens, performing unauthorized actions, or manipulating displayed data. This can lead to data breaches, unauthorized data modification, or reputational damage. The requirement for user interaction and authentication limits the attack surface but does not eliminate risk, especially in environments with many users or where privilege separation is weak. Organizations in sectors such as finance, healthcare, and government, which often use HCL products for internal applications, may face increased risk due to the sensitivity of their data. Additionally, the lack of a patch at the time of publication means organizations must rely on mitigations to reduce exposure. The impact on availability is negligible, but the potential for targeted attacks exploiting this vulnerability to gain footholds or escalate privileges within enterprise applications is a concern.

To mitigate this vulnerability effectively, European organizations should implement the following specific measures beyond generic patching advice: 1) Immediately restrict file upload capabilities in HCL Domino Volt applications to exclude .html and other potentially dangerous file types via custom file type filters or application-level validation. 2) Enforce strict content security policies (CSP) on deployed applications to limit the execution of inline scripts and restrict sources of executable code, thereby reducing the impact of any malicious JavaScript that might be uploaded. 3) Implement multi-factor authentication and strict privilege management to minimize the risk posed by authenticated attackers uploading malicious files. 4) Conduct thorough user training to raise awareness about the risks of interacting with untrusted uploaded content. 5) Monitor application logs and user activities for unusual file uploads or access patterns indicative of exploitation attempts. 6) If possible, isolate file upload directories from the web root or configure the web server to prevent execution of uploaded .html files. 7) Engage with HCL Software support channels to obtain updates on patches or official workarounds and apply them promptly once available. These targeted mitigations will reduce the likelihood and impact of exploitation until an official patch is released.