guzzlehttp/guzzle versions before 7.15.1 contain an information disclosure vulnerability in RedirectMiddleware. When the optional allow_redirects.referer setting is enabled, the middleware copies the URI fragment (the portion after #) from the referring request into the generated Referer header when following a same-scheme redirect (e.g., HTTPS to HTTPS). An attacker who controls the redirect destination can read this fragment from the incoming Referer header, potentially disclosing one-time login secrets, access tokens, state values, or other sensitive client data to a server never meant to receive it. The referer setting is disabled by default. Fixed in 7.15.1, which strips the fragment before generating the Referer value.
Weakness
The code transmits data to another actor, but a portion of the data includes sensitive information that should not be accessible to that actor.
Affected Software
| Name | Vendor | Start Version | End Version |
|---|---|---|---|
| Guzzle | Ubuntu | upstream | * |
Potential Mitigations
- Compartmentalize the system to have “safe” areas where trust boundaries can be unambiguously drawn. Do not allow sensitive data to go outside of the trust boundary and always be careful when interfacing with a compartment outside of the safe area.
- Ensure that appropriate compartmentalization is built into the system design, and the compartmentalization allows for and reinforces privilege separation functionality. Architects and designers should rely on the principle of least privilege to decide the appropriate time to use privileges and the time to drop privileges.
Related Attack Patterns
- https://cwe.mitre.org/data/definitions/12.html
- https://cwe.mitre.org/data/definitions/217.html
- https://cwe.mitre.org/data/definitions/612.html
- https://cwe.mitre.org/data/definitions/613.html
- https://cwe.mitre.org/data/definitions/618.html
- https://cwe.mitre.org/data/definitions/619.html
- https://cwe.mitre.org/data/definitions/621.html
- https://cwe.mitre.org/data/definitions/622.html
- https://cwe.mitre.org/data/definitions/623.html