CVE-2025-0557: Hyland Alfresco XSS Vulnerability

CVE-2025-0557 Overview

CVE-2025-0557 is a cross-site scripting (XSS) vulnerability affecting Hyland Alfresco Community Edition and Alfresco Enterprise Edition through version 6.2.2. The flaw resides in the URL Handler component and can be triggered via the /share/s/ path. Remote attackers can inject arbitrary script content without authentication or user interaction, executing code in the context of a victim's browser session. The exploit details have been publicly disclosed, increasing the risk of opportunistic abuse against unpatched deployments. Upgrading to Alfresco 7.0 remediates the issue. The vulnerability is categorized under [CWE-79] (Improper Neutralization of Input During Web Page Generation).

Critical Impact
Unauthenticated remote attackers can inject scripts into the Alfresco Share interface, enabling session-context script execution against authenticated users of the collaboration platform.

Affected Products

Hyland Alfresco Community Edition up to 6.2.2
Hyland Alfresco Enterprise Edition up to 6.2.2
URL Handler component servicing the /share/s/ endpoint

Discovery Timeline

2025-01-18 - CVE-2025-0557 published to NVD
2026-06-17 - Last updated in NVD database

Technical Details for CVE-2025-0557

Vulnerability Analysis

The vulnerability exists in the URL Handler component of Alfresco Share, specifically in code paths that process requests to /share/s/. User-supplied input reaches the response rendering layer without proper output encoding or input sanitization. An attacker can craft a URL containing script payloads that the application reflects back into the HTML response.

When a victim visits the crafted link, the injected JavaScript executes within the origin of the Alfresco deployment. This grants the attacker access to session cookies, cross-site request forgery (CSRF) tokens, and any actions available to the authenticated user. In content management platforms like Alfresco, this includes document access, workflow manipulation, and administrative operations if the victim holds elevated privileges.

Root Cause

The root cause is missing or insufficient neutralization of untrusted input in the URL Handler ([CWE-79]). Data passed through the /share/s/ endpoint is incorporated into rendered pages without contextual encoding for HTML, attribute, or JavaScript sinks. Alfresco 7.0 introduces the corrected input handling logic.

Attack Vector

Exploitation occurs over the network and requires no authentication or privileges. The attacker delivers a malicious link — via phishing email, chat, or an external site — targeting a user with an active Alfresco Share session. When the victim loads the link, the reflected payload executes in their browser. No local access or user interaction beyond clicking the link is required.

The vulnerability affects only confidentiality and integrity of user-scoped data within the browser context. It does not directly compromise the underlying server, though follow-on attacks such as session hijacking and privileged action execution are possible.

Detection Methods for CVE-2025-0557

Indicators of Compromise

Web server or reverse proxy logs showing requests to /share/s/ containing HTML entities, <script> tags, javascript: URIs, or event handler attributes such as onerror= and onload=.
URL-encoded payloads targeting the Share URL handler, including sequences such as %3Cscript%3E or %22%3E%3Cimg.
Referer headers from external domains preceding suspicious /share/s/ requests, indicating a link-based delivery vector.

Detection Strategies

Deploy web application firewall (WAF) signatures that inspect query strings and path parameters to /share/s/ for XSS payload patterns.
Correlate outbound HTTP requests from authenticated user sessions with anomalous internal Alfresco activity to identify session abuse following successful XSS execution.
Enable Content Security Policy (CSP) violation reporting to surface script execution attempts blocked in browsers.

Monitoring Recommendations

Alert on repeated 4xx/5xx responses from /share/s/ combined with encoded script payloads in access logs.
Monitor Alfresco Share audit logs for privileged actions initiated shortly after users load externally referred links.
Track browser telemetry from managed endpoints for JavaScript errors or CSP violations originating on the Alfresco domain.

How to Mitigate CVE-2025-0557

Immediate Actions Required

Upgrade Alfresco Community Edition and Enterprise Edition to version 7.0 or later, which contains the fix for the URL Handler flaw.
Inventory all Alfresco Share deployments and prioritize internet-exposed instances for immediate patching.
Invalidate existing user sessions after patching to force re-authentication and reduce the value of any stolen session tokens.

Patch Information

Hyland addresses CVE-2025-0557 in Alfresco version 7.0. Administrators running any release up to and including 6.2.2 must upgrade to a supported 7.x branch. Reference the vulnerability tracking entries at VulDB #292491 and VulDB CTI ID #292491 for additional context.

Workarounds

Deploy a WAF rule that blocks or sanitizes requests to /share/s/ containing script tags, event handlers, or javascript: URIs until the upgrade is complete.
Enforce a strict Content Security Policy on the Alfresco Share application to prevent inline script execution and restrict script sources.
Restrict network access to Alfresco Share so that only trusted networks or VPN users can reach the vulnerable endpoint.
Educate users to avoid clicking untrusted links referencing the corporate Alfresco domain until patching is complete.

bash

# Example NGINX rule to block obvious XSS payloads targeting the Share URL handler
location /share/s/ {
    if ($args ~* "(<|%3C)script|javascript:|onerror=|onload=") {
        return 403;
    }
    proxy_pass http://alfresco_backend;
}