Cargo between 1.68 and 1.96 incorrectly normalized the URLs of third-party registries using the sparse index protocol. If a hosting provider allowed multiple registries to be hosted with arbitrary names within the same domain, an attacker able to publish crates in a registry could obtain the credentials of others users of the same registry. The severity of the vulnerability is low, due to the extremely niche requirements needed to achieve the attack.
Weakness
The product defines policy namespaces and makes authorization decisions based on the assumption that a URL is canonical. This can allow a non-canonical URL to bypass the authorization.
Affected Software
| Name | Vendor | Start Version | End Version |
|---|---|---|---|
| Cargo | Rust-lang | 1.68.0 (including) | 1.96.0 (excluding) |
| Rustc-1.85 | Ubuntu | questing | * |
| Rustc-1.88 | Ubuntu | questing | * |
| Rustc-1.91 | Ubuntu | questing | * |
Extended Description
If an application defines policy namespaces and makes authorization decisions based on the URL, but it does not require or convert to a canonical URL before making the authorization decision, then it opens the application to attack. For example, if the application only wants to allow access to http://www.example.com/mypage, then the attacker might be able to bypass this restriction using equivalent URLs such as:
Therefore it is important to specify access control policy that is based on the path information in some canonical form with all alternate encodings rejected (which can be accomplished by a default deny rule).