A flaw was found in libsoup’s caching mechanism, SoupCache, where the HTTP Vary header is ignored when evaluating cached responses. This header ensures that responses vary appropriately based on request headers such as language or authentication. Without this check, cached content can be incorrectly reused across different requests, potentially exposing sensitive user information. While the issue is unlikely to affect everyday desktop use, it could result in confidentiality breaches in proxy or multi-user environments.
The code uses a cache that contains sensitive information, but the cache can be read by an actor outside of the intended control sphere.
| Name | Vendor | Start Version | End Version |
|---|---|---|---|
| Libsoup2.4 | Ubuntu | upstream | * |
| Libsoup3 | Ubuntu | upstream | * |