CVE-2025-55135 is a medium severity vulnerability identified in the Agora Foundation's Agora product, specifically in versions prior to commit 690ce56 of the fall23-Alpha1 release. The vulnerability is classified under CWE-434, which pertains to the unrestricted upload of files with dangerous types. The core issue arises from the server-side handling of profile picture uploads in the userController.js component. While the application intends to restrict uploaded image formats to PNG, JPEG, and WEBP, the server/routes/userRoutes.js file permits additional formats, including SVG. SVG files can contain embedded scripts, making them a vector for Cross-Site Scripting (XSS) attacks. This discrepancy allows an attacker to upload a malicious SVG file as a profile picture, which, when rendered in a victim's browser, can execute arbitrary JavaScript code. The CVSS v3.1 score is 6.4, indicating a medium severity level. The attack vector is network-based (AV:N), with low attack complexity (AC:L), requiring low privileges (PR:L), and no user interaction (UI:N). The scope is changed (S:C), meaning the vulnerability affects resources beyond the initially vulnerable component. The impact affects confidentiality and integrity at a low level but does not impact availability. No known exploits are currently reported in the wild, and no patches are linked yet, indicating that remediation may still be in progress or pending release. This vulnerability can be exploited by authenticated users with the ability to upload profile pictures, enabling them to inject malicious scripts that could compromise other users' sessions or steal sensitive information when those users view the malicious profile picture.

For European organizations using the Agora platform, this vulnerability poses a significant risk to user data confidentiality and system integrity. Exploitation could lead to session hijacking, credential theft, or unauthorized actions performed on behalf of legitimate users. Since the vulnerability requires authenticated access to upload profile pictures, insider threats or compromised accounts could be leveraged to propagate attacks. The cross-site scripting vector could also facilitate phishing or social engineering campaigns within the organization. Given the scope change, the impact could extend beyond the initial user context, potentially affecting administrative interfaces or other sensitive components. This could undermine trust in the platform, lead to regulatory compliance issues under GDPR due to data breaches, and cause reputational damage. Additionally, if the platform is integrated into critical communication or collaboration workflows, disruption or data leakage could have operational consequences.

Organizations should immediately audit and restrict allowed file upload types on the Agora platform, explicitly disallowing SVG files or any other formats capable of embedding executable scripts. Implement server-side validation that strictly enforces MIME type and file content verification rather than relying solely on file extensions. Employ Content Security Policy (CSP) headers to mitigate the impact of potential XSS payloads by restricting script execution sources. Ensure that user input, including uploaded file names and metadata, is properly sanitized and encoded before rendering. Monitor user uploads for suspicious files and establish alerting mechanisms for anomalous upload activity. Since no official patch is currently linked, organizations should engage with Agora Foundation for updates and apply patches promptly once available. Additionally, consider implementing multi-factor authentication to reduce the risk of account compromise and limit the privileges of users who can upload profile pictures. Regular security training for users to recognize phishing and suspicious activity can also reduce exploitation likelihood.