CVE-2026-67101: HCL BigFix Service Management SSRF Vulnerability

CVE-2026-67101 Overview

CVE-2026-67101 is a Server-Side Request Forgery (SSRF) vulnerability affecting HCL BigFix Service Management. The flaw resides in the product's search functionality and allows unauthenticated attackers to coerce the application server into issuing HTTP requests to internal systems. Because the request originates from the trusted BigFix server, attackers can reach hosts and services that are not directly exposed to the internet. The vulnerability is tracked under CWE-918: Server-Side Request Forgery.

Critical Impact
Unauthenticated network attackers can pivot through the BigFix Service Management server to probe internal networks, access cloud metadata endpoints, and read sensitive data from internal services.

Affected Products

HCL BigFix Service Management (search functionality)

Discovery Timeline

2026-09-18 - CVE-2026-67101 published to NVD
2026-09-21 - Last updated in NVD database

Technical Details for CVE-2026-67101

Vulnerability Analysis

The vulnerability exists in the search feature of HCL BigFix Service Management. The search component accepts a user-supplied URL or URL-like parameter and processes it server-side without adequate validation of the destination. As a result, the application server acts as a proxy for attacker-controlled requests. An attacker sends a crafted search request containing a target URL, and the server dispatches an HTTP request to that URL from within the internal network perimeter.

Because the request originates from the BigFix server, it inherits access to internal-only resources, including private IP ranges, service discovery endpoints, cloud instance metadata services, and administrative interfaces bound to loopback. The scope of impact extends beyond the vulnerable component, allowing attacker requests to reach systems the attacker could not otherwise contact.

Root Cause

The root cause is missing or insufficient validation of user-supplied URLs passed to the server-side request handler in the search functionality [CWE-918]. The application does not restrict outbound requests to an allowlist of destinations, nor does it block requests to private, link-local, or loopback address ranges.

Attack Vector

Exploitation requires only network access to the BigFix Service Management web interface. No authentication and no user interaction are required. An attacker submits a search request that includes a URL pointing at an internal service, such as http://169.254.169.254/latest/meta-data/ for cloud metadata, http://127.0.0.1:admin-port/ for local administrative endpoints, or internal RFC 1918 addresses. The server issues the request and, depending on the endpoint behavior, may return response content, timing information, or error data useful for reconnaissance.

No verified proof-of-concept code is publicly available. Refer to the
HCL Software Knowledge Base advisory for vendor-supplied technical details.

Detection Methods for CVE-2026-67101

Indicators of Compromise

Outbound HTTP requests from the BigFix Service Management server to internal IP ranges (10.0.0.0/8, 172.16.0.0/12, 192.168.0.0/16), loopback (127.0.0.0/8), or link-local (169.254.0.0/16) addresses.
Unusual entries in BigFix application logs where search parameters contain fully qualified URLs, IP addresses, or protocol schemes such as file://, gopher://, or dict://.
Anomalous DNS queries from the BigFix server to internal hostnames not associated with normal product operation.

Detection Strategies

Inspect web server and reverse-proxy logs for search endpoint requests containing URL-encoded parameters that decode to internal addresses or non-HTTP schemes.
Correlate outbound network flows from the BigFix server against a baseline of expected destinations, and alert on connections to private ranges or cloud metadata endpoints.
Deploy WAF signatures that detect SSRF payload patterns targeting the search parameter, including IPv6 loopback notations and decimal-encoded IP addresses.

Monitoring Recommendations

Enable verbose logging on the BigFix Service Management search component to capture full request parameters for forensic review.
Monitor egress traffic from the BigFix host through a network security tool and alert on connections to previously unseen internal destinations.
Track failed connection attempts from the BigFix server, which often indicate SSRF probing activity.

How to Mitigate CVE-2026-67101

Immediate Actions Required

Review the HCL Software Knowledge Base Article KB0133782 and apply the vendor-supplied fix as soon as available.
Restrict network egress from the BigFix Service Management server to only the destinations required for normal operation.
Place the BigFix web interface behind an authenticated reverse proxy or VPN if it is currently exposed to untrusted networks.

Patch Information

HCL has published guidance and remediation information in HCL Knowledge Base Article KB0133782. Administrators should consult the advisory for the fixed version, patch identifiers, and upgrade instructions specific to their deployment.

Workarounds

Configure a host-based or perimeter firewall to block outbound connections from the BigFix server to RFC 1918 ranges, 127.0.0.0/8, 169.254.0.0/16, and cloud metadata IPs where feasible.
Deploy a Web Application Firewall rule that rejects search requests containing URL schemes or IP literals in user-controlled parameters.
On cloud deployments, enforce Instance Metadata Service v2 (IMDSv2) to require session tokens, mitigating credential theft from metadata endpoints via SSRF.

bash

# Example iptables egress restriction on the BigFix host
iptables -A OUTPUT -d 169.254.169.254 -j DROP
iptables -A OUTPUT -d 127.0.0.0/8 ! -o lo -j DROP
iptables -A OUTPUT -d 10.0.0.0/8 -m owner --uid-owner bigfix -j DROP
iptables -A OUTPUT -d 172.16.0.0/12 -m owner --uid-owner bigfix -j DROP
iptables -A OUTPUT -d 192.168.0.0/16 -m owner --uid-owner bigfix -j DROP