CVE-2021-31216
📋 TL;DR
CVE-2021-31216 is a server-side request forgery (SSRF) vulnerability in Siren Investigate's built-in image proxy route that allows authenticated attackers to make arbitrary HTTP requests from the server. This affects all Siren Investigate installations before version 11.1.1 where the default-enabled image proxy feature is active. Attackers can potentially access internal services, exfiltrate data, or perform other malicious actions through the compromised server.
💻 Affected Systems
- Siren Investigate
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Attacker gains access to internal network services, exfiltrates sensitive data, or uses the server as a pivot point for further attacks on internal infrastructure.
Likely Case
Attacker accesses internal HTTP services, retrieves metadata from cloud services, or performs port scanning of internal network segments.
If Mitigated
Limited impact if network segmentation restricts outbound connections and internal services require additional authentication.
🎯 Exploit Status
Exploitation requires authenticated access to the Siren Investigate installation. The vulnerability is straightforward to exploit once access is obtained.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: 11.1.1
Vendor Advisory: https://docs.siren.io/siren-platform-user-guide/11.1/release-notes.html
Restart Required: Yes
Instructions:
1. Backup your Siren Investigate configuration and data. 2. Download and install Siren Investigate version 11.1.1 or later from the official vendor website. 3. Restart the Siren Investigate service. 4. Verify the installation is running the patched version.
🔧 Temporary Workarounds
Disable Image Proxy Feature
allDisable the vulnerable image proxy route if it's not required for your use case.
Modify Siren Investigate configuration to disable the image proxy feature. Consult Siren documentation for specific configuration parameters.
Network Segmentation
allRestrict outbound network connections from the Siren Investigate server to only necessary destinations.
Configure firewall rules to block outbound HTTP/HTTPS traffic from the Siren Investigate server except to required external services.
🧯 If You Can't Patch
- Implement strict network segmentation to limit the Siren Investigate server's outbound connections.
- Monitor for unusual outbound HTTP requests from the Siren Investigate server to detect potential exploitation.
🔍 How to Verify
Check if Vulnerable:
Check the Siren Investigate version. If it's earlier than 11.1.1, the system is vulnerable.Check Version:
Check the Siren Investigate web interface or configuration files for version information.Verify Fix Applied:
Verify the installed version is 11.1.1 or later and test that the image proxy feature no longer accepts arbitrary URLs.📡 Detection & Monitoring
Log Indicators:
- Unusual HTTP requests from the Siren Investigate server to internal or external services
- Image proxy requests with non-standard URLs or to unexpected domains
Network Indicators:
- HTTP traffic from Siren Investigate server to unexpected internal IP addresses or external domains
- Port scanning activity originating from the Siren Investigate server
SIEM Query:
source="siren-investigate" AND (url="*image-proxy*" OR method="GET" AND uri="*/api/image-proxy*") AND (dest_ip NOT IN ["allowed_domains"])