CVE-2024-11182
MDaemon Email Server Cross-Site Scripting (XSS) Vulnerability
Description
CVE-2024-11182 is a medium-severity cross-site scripting (XSS) vulnerability in the MDaemon Email Server affecting versions prior to 24.5.1c. The flaw allows a remote attacker to embed malicious JavaScript within an HTML email message using a specially crafted img tag. When a user views the email through MDaemon's webmail interface, the JavaScript payload executes in the context of the victim's browser session, potentially leading to session hijacking, credential theft, or unauthorized actions. CISA has added CVE-2024-11182 to the Known Exploited Vulnerabilities catalog with a remediation deadline of June 9, 2025, and its EPSS score of 12.93% at the 93rd percentile signals a high probability of active exploitation.
KEV Information
CVSS Score
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:NOpen in CalculatorAffected Products
| Vendor | Product | Version |
|---|---|---|
| mdaemon | mdaemon | < 24.5.1 |
References
- https://files.mdaemon.com/mdaemon/beta/RelNotes_en.html(Release Notes)
- https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2024-11182(US Government Resource)
Weakness Type
CWE-79: Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
CVE-2024-11182 is classified under CWE-79, commonly known as Cross-site Scripting (XSS). In the MDaemon Email Server, the webmail component fails to properly sanitize HTML content within email messages, specifically JavaScript embedded in img tags. This allows an attacker to inject malicious client-side scripts that execute when a victim views the crafted email, enabling session hijacking, credential theft, or phishing attacks within the trusted MDaemon webmail domain.
Learn more: CWE-79 — Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
Impact Analysis
CVE-2024-11182 carries a CVSS v3.1 base score of 6.1 (Medium) with an attack vector that is remotely exploitable over the network (AV:N), low attack complexity (AC:L), and no authentication required (PR:N), though user interaction is required (UI:R) as the victim must view the malicious email. The scope is changed (S:C), meaning the XSS payload can affect resources beyond the MDaemon webmail component, specifically the victim's browser and any other applications sharing the same session context. Confidentiality and integrity face low impact (C:L/I:L), as the attacker can access session cookies and perform limited actions on behalf of the victim. However, email servers are high-value targets because they process sensitive communications, and a successful XSS attack can serve as a stepping stone for deeper compromise including email account takeover, mail forwarding rule manipulation, and exfiltration of confidential communications. The EPSS score of 12.93% places this vulnerability in the 93rd percentile, confirming exploitation is probable.
Exploit Maturity
CVE-2024-11182 shows significant exploit maturity. CISA has confirmed active exploitation in the wild by including it in the Known Exploited Vulnerabilities catalog. The EPSS score of 12.93% at the 93rd percentile indicates that this vulnerability is among the most likely to be exploited across all tracked CVEs. While no standalone proof-of-concept exploit code is explicitly tagged in the NVD references, the nature of email-based XSS attacks is well understood and trivially reproducible by crafting an HTML email with malicious JavaScript in img tag attributes. The confirmed KEV status and the critical nature of email infrastructure make this vulnerability a high-priority remediation target.
Remediation
- Upgrade MDaemon Email Server immediately. Update to version 24.5.1c or later, which addresses the XSS vulnerability. Review the MDaemon release notes for detailed patch information.
- Implement email content filtering. Configure MDaemon's content filtering rules or deploy an email security gateway to strip or sanitize HTML content containing JavaScript, event handlers, and other potentially malicious elements before messages are rendered in the webmail interface.
- Deploy Content Security Policy (CSP) headers. Configure strict CSP rules on the MDaemon webmail server to prevent inline script execution and restrict allowed script sources, mitigating the impact of XSS payloads that bypass input sanitization.
- Monitor for suspicious email activity. Review mail logs for HTML emails containing unusual
imgtags with JavaScript event handlers such asonerror,onload, oronmouseover. Check for indicators of account compromise including unexpected forwarding rules, password changes, or login anomalies. - Consider disabling HTML email rendering. As an interim measure, configure MDaemon webmail to display emails in plain text mode, which eliminates the XSS attack surface at the cost of reduced email formatting.
Technical Details
CVE-2024-11182 is a cross-site scripting vulnerability in the MDaemon Email Server's webmail HTML rendering engine. The CVSS v3.1 vector string CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N confirms the attack is network-accessible, requires low complexity, needs no authentication, but depends on user interaction (the victim viewing the email). The changed scope indicates the payload affects contexts beyond the vulnerable email rendering component.
The vulnerability exists because MDaemon's webmail interface does not adequately sanitize HTML content within email messages before rendering. Specifically, JavaScript can be embedded within img tag attributes (such as onerror event handlers) that the webmail client processes without proper encoding or stripping. When a user views or previews the malicious email, the browser executes the embedded JavaScript with the permissions of the webmail session. This enables the attacker to access document.cookie for session theft, manipulate the DOM to present phishing content, or make authenticated API calls to the MDaemon server on behalf of the victim.
Frequently Asked Questions
Is CVE-2024-11182 being actively exploited?
Yes. CISA has confirmed active exploitation by adding CVE-2024-11182 to the Known Exploited Vulnerabilities catalog. The EPSS score of 12.93% at the 93rd percentile further indicates high exploitation probability.
What products are affected by CVE-2024-11182?
MDaemon Email Server versions prior to 24.5.1c are affected. Organizations should upgrade to version 24.5.1c or later to remediate the XSS vulnerability.
How do I fix CVE-2024-11182?
Update MDaemon Email Server to version 24.5.1c or later. Additionally, implement content filtering for HTML emails, deploy CSP headers on the webmail interface, and monitor for suspicious email content containing JavaScript in image tags.
How severe is CVE-2024-11182?
CVE-2024-11182 has a CVSS v3.1 base score of 6.1 (Medium). While the direct impact is rated low for both confidentiality and integrity, the changed scope and the critical nature of email infrastructure elevate the real-world risk. The EPSS score of 12.93% at the 93rd percentile confirms exploitation is likely.
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