CVE-2025-2150: Hgiga C&Cm@il Stored XSS Vulnerability

CVE-2025-2150 Overview

CVE-2025-2150 is a stored Cross-Site Scripting (XSS) vulnerability in HGiga C&Cm@il, a mail collaboration product. Authenticated attackers with regular user privileges can send emails containing malicious JavaScript. The payload executes in a recipient's browser when the email is opened. The issue maps to [CWE-79] (Improper Neutralization of Input During Web Page Generation). Taiwan's TW-CERT published the advisory disclosing the flaw.

Critical Impact
Authenticated users can inject JavaScript that runs in the context of any recipient's webmail session, enabling session theft, credential harvesting, and unauthorized actions within the mail application.

Affected Products

HGiga C&Cm@il (all versions prior to the vendor-supplied fix)

Discovery Timeline

2025-03-10 - CVE-2025-2150 published to NVD
2026-06-17 - Last updated in NVD database

Technical Details for CVE-2025-2150

Vulnerability Analysis

CVE-2025-2150 is a stored XSS flaw in the webmail rendering component of HGiga C&Cm@il. The application fails to properly neutralize HTML and JavaScript content within message bodies. When a recipient opens a crafted message, the browser interprets attacker-supplied script as trusted content originating from the webmail domain.

Exploitation requires low privileges. Any authenticated user of the mail platform can craft the payload. It also requires user interaction because the victim must open the message. The scope is changed, meaning the injected script executes in the security context of the webmail application and can affect resources beyond the attacker's own account.

Successful exploitation lets attackers read mailbox contents, exfiltrate session cookies, submit forms on behalf of the victim, or pivot to further internal phishing from a trusted mailbox.

Root Cause

The root cause is missing output encoding and insufficient input sanitization when rendering email content in the web interface. HTML tags and event-handler attributes carried in the message body are not stripped or escaped before being written into the DOM.

Attack Vector

The attack vector is network-based through the mail transport. An attacker with valid credentials composes an email containing HTML with embedded JavaScript, such as <img> tags with onerror handlers or <script> blocks that survive server-side processing. The message is delivered to targeted recipients. When a victim opens the message in the C&Cm@il webmail client, the payload executes in the browser under the webmail origin. See the TW-CERT Advisory on Security for vendor-coordinated details.

Detection Methods for CVE-2025-2150

Indicators of Compromise

Inbound or internally routed emails containing <script> tags, javascript: URIs, or event-handler attributes such as onerror, onload, or onclick in the HTML body.
Webmail sessions issuing unexpected XHR or fetch requests to external domains shortly after a user opens a message.
Anomalous mailbox actions (mass forwarding rules, new filters, sent items) originating from user accounts without corresponding interactive logins.

Detection Strategies

Deploy mail-gateway content inspection to flag HTML messages containing inline scripts or suspicious event handlers before delivery to C&Cm@il.
Review webmail application logs for message-render events correlated with outbound requests to attacker-controlled infrastructure.
Hunt for phishing-like content patterns in stored mail using regex-based scans across the message store.

Monitoring Recommendations

Enable browser Content Security Policy (CSP) reporting to capture blocked inline-script executions in the webmail origin.
Alert on newly created auto-forward rules, delegate access, or OAuth grants on C&Cm@il accounts.
Track failed and successful authentications following message-open events to identify session-hijack follow-through.

How to Mitigate CVE-2025-2150

Immediate Actions Required

Apply the HGiga-supplied patch for C&Cm@il as referenced in the TW-CERT Advisory on Security.
Force password resets and invalidate active webmail sessions for accounts that received suspicious HTML mail.
Restrict internal message-composition privileges for accounts that do not require external mail sending.

Patch Information

HGiga has issued a security update addressed through the TW-CERT coordinated disclosure. Administrators should contact HGiga support and consult the TW-CERT Incident Response Report for version-specific remediation guidance. No public patch commit or CPE version boundary is listed in NVD at time of writing.

Workarounds

Configure the webmail client to render messages as plain text until the patch is applied.
Strip or quarantine HTML messages containing <script> tags and inline event handlers at the mail gateway.
Enforce a strict CSP on the webmail application that disallows inline scripts and untrusted script sources.

bash

# Example mail-gateway rule (pseudocode) to quarantine HTML with inline scripts
if message.content_type == "text/html" and \
   regex_match(message.body, "<script|onerror=|onload=|javascript:"):
    quarantine(message, reason="potential CVE-2025-2150 XSS payload")