CVE-2026-6220: HummerRisk SSRF Vulnerability

CVE-2026-6220 Overview

A Server-Side Request Forgery (SSRF) vulnerability has been identified in HummerRisk up to version 1.5.0. This vulnerability affects the ServerService.addServer function within the ServerService.java file of the Video File Download URL Handler component. Manipulation of the streamIp argument allows attackers to conduct SSRF attacks remotely. The exploit has been publicly disclosed, and despite early contact, the vendor has not responded to disclosure efforts.

Critical Impact

Remote attackers with high privileges can leverage this SSRF vulnerability to forge server-side requests, potentially accessing internal services, sensitive resources, or pivoting to other systems within the network infrastructure.

Affected Products

• HummerRisk versions up to 1.5.0
• Video File Download URL Handler component
• ServerService.java - ServerService.addServer function

Discovery Timeline

• April 13, 2026 - CVE-2026-6220 published to NVD
• April 13, 2026 - Last updated in NVD database

Technical Details for CVE-2026-6220

Vulnerability Analysis

This Server-Side Request Forgery (SSRF) vulnerability resides in the ServerService.addServer function within HummerRisk's Video File Download URL Handler component. The vulnerability allows authenticated attackers with elevated privileges to manipulate the streamIp parameter to make arbitrary HTTP requests from the server. SSRF vulnerabilities of this nature can enable attackers to bypass network segmentation, access internal services not exposed to the internet, scan internal networks, or retrieve sensitive data from metadata services in cloud environments.

The attack can be launched remotely over the network, though it requires high-level privileges to exploit successfully. When exploited, an attacker gains the ability to read internal resources, potentially modify data, or cause limited denial of service conditions on the target system.

Root Cause

The root cause of this vulnerability is insufficient input validation and sanitization of the streamIp argument in the ServerService.addServer function. The application fails to properly validate user-supplied URL inputs before making server-side HTTP requests, allowing attackers to specify arbitrary internal or external destinations. This lack of URL scheme and destination validation is classified as CWE-918 (Server-Side Request Forgery).

Attack Vector

The attack is conducted remotely over the network. An authenticated attacker with high privileges can submit a crafted request to the Video File Download URL Handler endpoint, manipulating the streamIp parameter to specify internal network addresses, cloud metadata endpoints (such as http://169.254.169.254/), or other sensitive resources. The server then makes requests to these attacker-controlled destinations on behalf of the vulnerable application.

The vulnerability has been publicly documented with technical details available through the GitHub Issue Discussion and VulDB entry.

Detection Methods for CVE-2026-6220

Indicators of Compromise

• Unusual outbound HTTP requests from the HummerRisk application server to internal IP ranges or localhost addresses
• Server-side requests targeting cloud metadata endpoints such as 169.254.169.254
• Unexpected network traffic patterns from the application tier to infrastructure or management services
• Log entries showing unusual values in the streamIp parameter of ServerService.addServer requests

Detection Strategies

• Monitor application logs for the ServerService.addServer function calls with suspicious streamIp values containing internal IP addresses, localhost references, or cloud metadata endpoints
• Implement network-level monitoring to detect anomalous outbound connections from application servers to internal infrastructure
• Deploy web application firewall (WAF) rules to detect SSRF attack patterns in HTTP request parameters
• Enable audit logging for all Video File Download URL Handler operations

Monitoring Recommendations

• Configure alerting for any requests where streamIp contains private IP ranges (10.0.0.0/8, 172.16.0.0/12, 192.168.0.0/16)
• Monitor for DNS lookups to internal hostnames or metadata service endpoints initiated by the application
• Track authentication events to identify potentially compromised high-privilege accounts used in exploitation attempts

How to Mitigate CVE-2026-6220

Immediate Actions Required

• Restrict network access to the HummerRisk Video File Download URL Handler endpoint to trusted sources only
• Implement network-level controls to prevent the application server from making requests to internal IP ranges and cloud metadata services
• Review and audit accounts with high-level privileges that could be used to exploit this vulnerability
• Consider temporarily disabling the affected Video File Download functionality if not critical to operations

Patch Information

At the time of publication, the vendor (HummerRisk) has not responded to disclosure attempts and no official patch is available. Organizations using affected versions should implement the workarounds below and monitor for vendor updates. For additional technical details, refer to the VulDB Vulnerability Entry #357141.

Workarounds

• Implement strict input validation on the streamIp parameter to allow only whitelisted external domains
• Deploy network segmentation to isolate the HummerRisk application from sensitive internal services
• Use a web application firewall (WAF) to block requests containing suspicious URL patterns in the streamIp field
• Configure egress filtering to prevent the application server from accessing internal networks or cloud metadata endpoints

# Example: Block outbound connections to metadata services using iptables
iptables -A OUTPUT -d 169.254.169.254 -j DROP
iptables -A OUTPUT -d 10.0.0.0/8 -j DROP
iptables -A OUTPUT -d 172.16.0.0/12 -j DROP
iptables -A OUTPUT -d 192.168.0.0/16 -j DROP