CVE-2025-51962 is an HTML Injection vulnerability identified in MicroStudio version 24.01.29, specifically within the comment section of project pages. The vulnerability arises from insufficient sanitization of user-supplied input in the text parameter of the add_project_comment function, allowing remote attackers to inject arbitrary HTML or JavaScript code. This type of injection falls under CWE-79, which pertains to improper neutralization of input during web page generation. The vulnerability can be exploited remotely without requiring authentication, although it requires user interaction (e.g., a victim viewing the malicious comment). Successful exploitation can lead to the execution of malicious scripts in the context of the victim’s browser, potentially enabling session hijacking, credential theft, phishing attacks, or defacement of the affected web pages. The CVSS v3.1 base score is 6.1, indicating a medium severity level, with attack vector network (AV:N), low attack complexity (AC:L), no privileges required (PR:N), user interaction required (UI:R), scope changed (S:C), and low impact on confidentiality and integrity (C:L, I:L), with no impact on availability (A:N). No patches or fixes have been published yet, and there are no known exploits in the wild. The vulnerability’s scope is limited to users interacting with the comment section, but the impact on confidentiality and integrity can be significant if exploited effectively.

For European organizations using MicroStudio 24.01.29, this vulnerability poses risks primarily to confidentiality and integrity. Attackers could leverage the HTML Injection to execute malicious scripts, potentially stealing session cookies, redirecting users to phishing sites, or manipulating displayed content. This can lead to unauthorized access to sensitive project data or credentials. Although availability is not directly impacted, the reputational damage and potential data breaches could have regulatory and financial consequences, especially under GDPR. Organizations with collaborative development environments or public-facing project pages are particularly vulnerable. The requirement for user interaction limits automated exploitation but does not eliminate risk, as social engineering could be used to lure users into triggering the payload. The absence of patches increases exposure time, emphasizing the need for proactive mitigation. The medium CVSS score reflects a balanced risk, but the real-world impact depends on the extent of MicroStudio deployment and user exposure.

To mitigate CVE-2025-51962, organizations should implement strict input validation and output encoding on the add_project_comment function to neutralize HTML and script content. Employing a whitelist approach to allow only safe HTML tags or completely disallowing HTML input in comments can prevent injection. Web Application Firewalls (WAFs) can be configured to detect and block suspicious payloads targeting the comment section. User education on recognizing phishing and suspicious links is critical to reduce successful exploitation via social engineering. Monitoring logs for unusual comment submissions or script injections can help detect attempted attacks. Until an official patch is released, consider disabling the comment functionality or restricting it to trusted users only. Regularly update MicroStudio to the latest versions once patches become available. Additionally, applying Content Security Policy (CSP) headers can limit the impact of injected scripts by restricting script execution sources.