CVE-2020-15865
📋 TL;DR
This vulnerability allows remote attackers to execute arbitrary C# code on servers running vulnerable versions of Stimulsoft Reports by embedding malicious scripts in report XML files. Any organization using Stimulsoft Reports 2013.1.1600.0 for server-side report processing is affected. Attackers can achieve full server compromise through this remote code execution flaw.
💻 Affected Systems
- Stimulsoft Reports
📦 What is this software?
Reports by Stimulsoft
⚠️ Risk & Real-World Impact
Worst Case
Complete server takeover with administrative privileges, data exfiltration, lateral movement to other systems, and persistent backdoor installation.
Likely Case
Server compromise leading to data theft, cryptocurrency mining, or ransomware deployment on affected systems.
If Mitigated
Limited impact with proper network segmentation, application whitelisting, and strict input validation preventing exploitation.
🎯 Exploit Status
Exploitation is straightforward - attackers simply need to craft a malicious report XML file with base64-encoded C# scripts and upload it to the vulnerable server.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Later versions after 2013.1.1600.0
Vendor Advisory: https://www.stimulsoft.com/en/support/security
Restart Required: Yes
Instructions:
1. Upgrade to the latest version of Stimulsoft Reports. 2. Replace all vulnerable DLLs with patched versions. 3. Restart the application/service. 4. Test report processing functionality.
🔧 Temporary Workarounds
Disable report upload functionality
allRemove or disable the ability to upload external report files to the server.
Implement strict file validation
allAdd server-side validation to reject XML files containing base64-encoded scripts or suspicious content.
🧯 If You Can't Patch
- Network segmentation: Isolate Stimulsoft servers from critical systems and internet access.
- Application control: Implement whitelisting to prevent execution of unauthorized code.
🔍 How to Verify
Check if Vulnerable:
Check the Stimulsoft Reports assembly version - if it's 2013.1.1600.0, the system is vulnerable.Check Version:
Get-ChildItem -Path 'C:\Program Files\Stimulsoft\' -Recurse -Include '*.dll' | Select-Object Name, VersionInfoVerify Fix Applied:
Verify the Stimulsoft Reports version is updated beyond 2013.1.1600.0 and test with safe report files.📡 Detection & Monitoring
Log Indicators:
- Unusual report file uploads
- Failed compilation attempts
- Unexpected process execution from report processing
Network Indicators:
- Large XML files being uploaded to report endpoints
- Outbound connections from report servers to unknown destinations
SIEM Query:
source="web_server" AND (uri="*/report/upload*" OR uri="*/process/report*") AND file_size>100KB