CVE-2021-34427 – This vulnerability allows remote attackers to e... (How to Fix)

Q: What is the severity of CVE-2021-34427?

CVE-2021-34427 has a CVSS score of 9.8 (CRITICAL). This vulnerability allows remote attackers to execute arbitrary Java Server Pages (JSP) code on Eclipse BIRT servers by injecting malicious code through query parameters. Attackers can create accessible JSP files in the BIRT viewer directory, leading to remote code execution. Organizations using Eclipse BIRT versions 4.8.0 or earlier for business intelligence reporting are affected.

📋 TL;DR

This vulnerability allows remote attackers to execute arbitrary Java Server Pages (JSP) code on Eclipse BIRT servers by injecting malicious code through query parameters. Attackers can create accessible JSP files in the BIRT viewer directory, leading to remote code execution. Organizations using Eclipse BIRT versions 4.8.0 or earlier for business intelligence reporting are affected.

💻 Affected Systems

Products:

Eclipse Business Intelligence and Reporting Tools (BIRT)

Versions: 4.8.0 and earlier

Operating Systems: All platforms running Java

Default Config Vulnerable: ⚠️ Yes

Notes: Affects BIRT Viewer component specifically. Any deployment using BIRT for report generation is vulnerable.

📦 What is this software?

Business Intelligence And Reporting Tools by Eclipse

View all CVEs affecting Business Intelligence And Reporting Tools →

⚠️ Risk & Real-World Impact

🔴

Worst Case

Full system compromise with attacker gaining complete control over the server, data exfiltration, lateral movement within the network, and persistent backdoor installation.

🟠

Likely Case

Remote code execution allowing attackers to run arbitrary commands, access sensitive data, modify reports, and potentially pivot to other systems.

🟢

If Mitigated

Limited impact with proper network segmentation, application firewalls, and monitoring detecting exploitation attempts.

🌐 Internet-Facing: HIGH - Directly exploitable via HTTP requests without authentication, making internet-facing instances immediate targets.

🏢 Internal Only: HIGH - Even internally, this provides attackers with initial foothold for lateral movement and privilege escalation.

🎯 Exploit Status

Public PoC: ⚠️ Yes

Weaponized: CONFIRMED

Unauthenticated Exploit: ⚠️ Yes

Complexity: LOW

Multiple public exploit scripts and detailed write-ups exist. Attack requires only HTTP access to vulnerable endpoint.

🛠️ Fix & Mitigation

✅ Official Fix

Patch Version: 4.9.0 and later

Vendor Advisory: https://bugs.eclipse.org/bugs/show_bug.cgi?id=538142

Restart Required: Yes

Instructions:

1. Download Eclipse BIRT version 4.9.0 or later from official Eclipse repository. 2. Backup current BIRT installation and configuration. 3. Replace existing BIRT installation with patched version. 4. Restart application server hosting BIRT. 5. Verify reports function correctly.

🔧 Temporary Workarounds

Disable BIRT Viewer

all

Remove or disable the BIRT Viewer component if not required for business operations

Remove BIRT Viewer WAR file from application server deployment directory

Web Application Firewall Rules

all

Block malicious query parameters containing JSP injection patterns

Add WAF rule to block requests containing suspicious JSP tags or script patterns in query parameters

🧯 If You Can't Patch

Implement strict network segmentation to isolate BIRT servers from sensitive systems
Deploy web application firewall with rules specifically blocking JSP injection patterns in query parameters

🔍 How to Verify

Check if Vulnerable:

Check BIRT version via web interface or examine BIRT installation files for version information. Versions 4.8.0 or earlier are vulnerable.

Check Version:

Check BIRT installation directory for version.txt or examine web application metadata

Verify Fix Applied:

Confirm BIRT version is 4.9.0 or later. Test that JSP file creation via query parameters is no longer possible.

📡 Detection & Monitoring

Log Indicators:

Unusual JSP file creation in BIRT directories
HTTP requests with suspicious query parameters containing JSP tags
Multiple failed attempts followed by successful JSP file creation

Network Indicators:

HTTP POST/GET requests to BIRT endpoints with encoded JSP content in parameters
Unusual outbound connections from BIRT server post-exploitation

SIEM Query:

source="birt_logs" AND ("jsp" OR "script" OR "<%=") AND ("query" OR "parameter")

📊 Metadata

CVE ID: CVE-2021-34427

CVSS v3 Score: 9.8 (CRITICAL)

CVSS Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

CWE: CWE-20

Published: June 25, 2021

Last Updated: November 21, 2024

🔗 References

http://packetstormsecurity.com/files/170326/Eclipse-Business-Intelligence-Reporting-Tool-4.11.0-Remote-Code-Execution.html Exploit,Third Party Advisory
http://seclists.org/fulldisclosure/2022/Dec/30 Exploit,Mailing List,Third Party Advisory
https://bugs.eclipse.org/bugs/show_bug.cgi?id=538142 Exploit,Issue Tracking,Patch,Vendor Advisory
http://packetstormsecurity.com/files/170326/Eclipse-Business-Intelligence-Reporting-Tool-4.11.0-Remote-Code-Execution.html Exploit,Third Party Advisory
http://seclists.org/fulldisclosure/2022/Dec/30 Exploit,Mailing List,Third Party Advisory
https://bugs.eclipse.org/bugs/show_bug.cgi?id=538142 Exploit,Issue Tracking,Patch,Vendor Advisory

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