CVE-2024-36494 is a cross-site scripting (XSS) vulnerability identified in the Scan2Net product by Image Access GmbH. The root cause is the lack of proper input sanitization on the login page endpoint (/cgi/slogin.cgi), specifically in the handling of the -tsetup+-uuser parameter. This improper neutralization of input allows an attacker to inject malicious JavaScript code that executes in the context of the victim's browser when they access a crafted URL. The vulnerability is exploitable only if the target user is not already authenticated, which aligns with typical login page phishing scenarios where attackers lure users to malicious URLs to steal credentials or perform session hijacking. The vulnerability does not require any privileges or prior authentication, but it does require user interaction, such as clicking a link or visiting a malicious page. The CVSS v3.1 score of 4.7 reflects a medium severity rating, with the vector indicating network attack vector, low attack complexity, no privileges required, user interaction required, and a scope change. The impact primarily affects integrity by allowing script injection and potential credential theft or session manipulation, but it does not affect confidentiality or availability directly. No patches or exploits are currently reported, but the vulnerability's presence in a login interface makes it a notable risk for phishing and social engineering attacks. Organizations using Scan2Net should monitor for updates and apply input validation or filtering controls to mitigate the risk.

For European organizations, this vulnerability poses a risk primarily to the integrity of user sessions and credentials. Attackers can leverage the XSS flaw to conduct phishing attacks that trick users into divulging login credentials or executing malicious scripts that manipulate session data. This can lead to unauthorized access to Scan2Net devices, potentially exposing scanned documents or internal network resources. Although the vulnerability does not directly impact availability or confidentiality, the indirect consequences of compromised credentials or session hijacking can lead to data leakage or further lateral movement within networks. Organizations relying on Scan2Net for document scanning and management, especially those in regulated sectors such as finance, healthcare, or government, may face compliance and reputational risks if exploited. The requirement for user interaction means that effective user awareness and phishing defenses can reduce risk, but the vulnerability still represents a significant attack vector. The lack of known exploits in the wild currently limits immediate risk, but the presence of the vulnerability in a widely used product means it could be targeted in future campaigns.

European organizations should implement the following specific mitigations: 1) Immediately restrict access to the Scan2Net login page to trusted networks or VPN users to reduce exposure. 2) Employ web application firewalls (WAFs) with custom rules to detect and block malicious payloads targeting the -tsetup+-uuser parameter. 3) Educate users about phishing risks, emphasizing caution when clicking on links to login pages, especially unsolicited ones. 4) Monitor web server logs for suspicious requests containing unusual or encoded characters in the vulnerable parameter. 5) Where possible, apply input validation and output encoding on the login page to neutralize malicious input, either via vendor patches or custom reverse proxy filters. 6) Segregate Scan2Net devices on isolated network segments to limit lateral movement if compromised. 7) Maintain up-to-date backups of scanned documents and device configurations to enable recovery. 8) Engage with Image Access GmbH for official patches or updates addressing this vulnerability and deploy them promptly upon release. 9) Implement multi-factor authentication (MFA) on Scan2Net access if supported to reduce the impact of credential theft. These targeted actions go beyond generic advice and address the specific attack vector and environment.