CVE-2024-2593: AMSS++ Cross-Site Scripting Vulnerability

CVE-2024-2593 Overview

CVE-2024-2593 is a reflected Cross-Site Scripting (XSS) vulnerability in AMSS++ version 4.31, a web-based radio station management application. The flaw resides in /amssplus/modules/book/main/bookdetail_group.php, where the b_id parameter is not sufficiently encoded before being reflected in the HTTP response. A remote attacker can craft a malicious URL and deliver it to an authenticated user, executing arbitrary JavaScript in the victim's browser context. Successful exploitation enables session cookie theft and impersonation of the authenticated user. The vulnerability is classified under CWE-79: Improper Neutralization of Input During Web Page Generation.

Critical Impact
Attackers can hijack authenticated sessions of AMSS++ users by tricking them into visiting a crafted URL, gaining access to the radio management platform.

Affected Products

AMSS++ version 4.31
Deployments exposing /amssplus/modules/book/main/bookdetail_group.php
Any AMSS++ installation without input sanitization patches applied

Discovery Timeline

2024-03-18 - CVE-2024-2593 published to NVD
2026-06-17 - Last updated in NVD database

Technical Details for CVE-2024-2593

Vulnerability Analysis

The vulnerability is a reflected XSS flaw in the AMSS++ book module. The PHP script bookdetail_group.php accepts the b_id query parameter and includes its value in the generated HTML without applying output encoding or context-aware sanitization. Because the reflected content executes as script in the victim's browser, an attacker gains the ability to run arbitrary JavaScript within the AMSS++ origin.

Exploitation requires user interaction: the target must click a crafted link while authenticated to AMSS++. The scope change indicated in the CVSS vector reflects that injected script executes in a security context beyond the vulnerable component itself, allowing access to session cookies, DOM data, and authenticated API endpoints.

Root Cause

The root cause is missing output encoding of user-controlled input. The b_id parameter received via HTTP request is echoed into the response body without HTML entity encoding or type validation. AMSS++ 4.31 does not enforce contextual escaping when rendering this parameter, so any script payload supplied by the attacker becomes executable markup.

Attack Vector

The attacker constructs a URL targeting bookdetail_group.php with a JavaScript payload embedded in the b_id parameter. The link is delivered through phishing, chat, or an attacker-controlled page. When an authenticated AMSS++ user follows the link, the malicious script executes in their browser session. The script can then exfiltrate session cookies to an attacker-controlled endpoint, submit forged requests as the victim, or manipulate the rendered interface. Refer to the INCIBE Security Advisory on AMSSPlus Vulnerabilities for additional technical detail.

Detection Methods for CVE-2024-2593

Indicators of Compromise

HTTP requests to /amssplus/modules/book/main/bookdetail_group.php containing <script>, javascript:, onerror=, or URL-encoded equivalents in the b_id parameter
Outbound browser requests from AMSS++ user sessions to unfamiliar external domains carrying cookie values
Unexpected authenticated actions performed by legitimate AMSS++ accounts shortly after a link click

Detection Strategies

Deploy web application firewall (WAF) rules that inspect the b_id parameter for HTML tags, script keywords, and event handler patterns
Enable server-side logging of full query strings on the AMSS++ web server for retroactive analysis
Correlate reflected script patterns in access logs with subsequent authentication anomalies from the same user

Monitoring Recommendations

Monitor AMSS++ access logs for high-entropy or encoded payloads targeting the book module endpoints
Alert on Content Security Policy (CSP) violation reports originating from AMSS++ page loads
Track outbound HTTP traffic from user workstations to non-corporate domains immediately following AMSS++ URL visits

How to Mitigate CVE-2024-2593

Immediate Actions Required

Restrict access to the AMSS++ application to trusted networks or VPN users until a vendor patch is applied
Instruct authenticated users to avoid clicking AMSS++ links from untrusted sources such as email or chat
Configure the application session cookies with HttpOnly and Secure flags to reduce cookie theft impact

Patch Information

No vendor advisory or patched version is listed in the NVD entry for AMSS++ 4.31. Administrators should contact the AMSS++ project and monitor the INCIBE Security Advisory on AMSSPlus Vulnerabilities for release information. Upgrade to any version later than 4.31 once the vendor confirms the b_id parameter is properly encoded.

Workarounds

Deploy a WAF rule blocking requests to bookdetail_group.php when b_id contains non-numeric characters
Apply a strict Content Security Policy that disallows inline scripts on AMSS++ responses
Enforce short session lifetimes and re-authentication for sensitive AMSS++ actions to limit stolen cookie value

bash

# Example ModSecurity rule blocking script payloads in the b_id parameter
SecRule ARGS:b_id "@rx (?i)(<script|javascript:|onerror=|onload=|%3Cscript)" \
    "id:1002593,phase:2,deny,status:403,\
    msg:'CVE-2024-2593 AMSS++ XSS attempt in b_id parameter',\
    tag:'CWE-79'"