Request URL override
Description: Request URL override
Some applications and frameworks support HTTP headers that can be used to override parts of the request URL, potentially affecting the routing and processing of the request.
Intermediate systems are often oblivious to these headers. In the case of reverse proxies and web application firewalls, this can lead to security rulesets being bypassed. If a caching system is in place, this may enable cache poisoning attacks. These headers may also enable forging of log entries.
Even if the application is intended to be accessed directly, some visitors may be using a corporate proxy enabling localised cache poisoning.
Remediation: Request URL override
To fully resolve this issue, locate the component that processes the affected headers, and disable it entirely. If you are using a framework, applying any pending security updates may do this for you.
If this isn't practical, an alternative workaround is to configure an intermediate system to automatically strip the affected headers before they are processed.
- Web Security Academy: HTTP Host header attacks
- Web Security Academy: Web cache poisoning
- Practical Web Cache Poisoning
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