Silverstripe Hostname, IP and Protocol Spoofing through HTTP Headers
In it's default configuration, SilverStripe trusts all originating IPs to include HTTP headers for Hostname, IP and Protocol. This enables reverse proxies to forward requests while still retaining the original request information. Trusted IPs can be limited via the SS_TRUSTED_PROXY_IPS constant. Even with this restriction in place, SilverStripe trusts a variety of HTTP headers due to different proxy notations (e.g. X-Forwarded-For vs. Client-IP). Unless a proxy explicitly unsets invalid HTTP headers from connecting clients, this can lead to spoofing requests being passed through trusted proxies.
The impact of spoofed headers can include Director::forceSSL() not being enforced, SS_HTTPRequest->getIP() returning a wrong IP (disabling any IP restrictions), and spoofed hostnames circumventing any hostname-specific restrictions enforced in SilverStripe Controllers.
Regardless on running a reverse proxy in your hosting infrastructure, please follow the instructions on Secure Coding: Request hostname forgery in order to opt-in to these protections. If your website is not behind a reverse proxy, you might already be protected if using Apache with mod_env enabled, and you have the following line in your .htaccess file: SetEnv BlockUntrustedIPs true.
| Software | From | Fixed in |
|---|---|---|
silverstripe / framework
|
- | 3.1.17 |
|
silverstripe / framework
|
3.2.0 | 3.2.2 |
|
silverstripe / framework
|
3.3.0-beta1 | 3.3.0 |
- https://github.com/FriendsOfPHP/security-advisories/blob/master/silverstripe/framework/SS-2016-003-1.yaml
- https://github.com/silverstripe/silverstripe-framework/commit/37059eb6b3546f304e9c031abca0f096ddb175c6
- https://github.com/silverstripe/silverstripe-framework/commit/893e49703de4aa1855b5364919cbb0826f754fbf
- https://github.com/silverstripe/silverstripe-framework/commit/faa94d51d570788dcebc2f2ef6e9de4d179ce1e4
- https://www.silverstripe.org/download/security-releases/ss-2016-003
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Frequently Asked Questions
A security vulnerability is a weakness in software, hardware, or configuration that can be exploited to compromise confidentiality, integrity, or availability. Many vulnerabilities are tracked as CVEs (Common Vulnerabilities and Exposures), which provide a standardized identifier so teams can coordinate patching, mitigation, and risk assessment across tools and vendors.
CVSS (Common Vulnerability Scoring System) estimates technical severity, but it doesn't automatically equal business risk. Prioritize using context like internet exposure, affected asset criticality, known exploitation (proof-of-concept or in-the-wild), and whether compensating controls exist. A "Medium" CVSS on an exposed, production system can be more urgent than a "Critical" on an isolated, non-production host.
A vulnerability is the underlying weakness. An exploit is the method or code used to take advantage of it. A zero-day is a vulnerability that is unknown to the vendor or has no publicly available fix when attackers begin using it. In practice, risk increases sharply when exploitation becomes reliable or widespread.
Recurring findings usually come from incomplete Asset Discovery, inconsistent patch management, inherited images, and configuration drift. In modern environments, you also need to watch the software supply chain: dependencies, containers, build pipelines, and third-party services can reintroduce the same weakness even after you patch a single host. Unknown or unmanaged assets (often called Shadow IT) are a common reason the same issues resurface.
Use a simple, repeatable triage model: focus first on externally exposed assets, high-value systems (identity, VPN, email, production), vulnerabilities with known exploits, and issues that enable remote code execution or privilege escalation. Then enforce patch SLAs and track progress using consistent metrics so remediation is steady, not reactive.
SynScan combines attack surface monitoring and continuous security auditing to keep your inventory current, flag high-impact vulnerabilities early, and help you turn raw findings into a practical remediation plan.