libcurl might in some circumstances reuse the wrong connection for SMB(S) transfers.
libcurl features a pool of recent connections so that subsequent requests can reuse an existing connection to avoid overhead.
When reusing a connection a range of criteria must be met. Due to a logical error in the code, a network transfer operation that was requested by an application could wrongfully reuse an existing SMB connection to the same server that was using a different share than the new subsequent transfer should.
This could in unlucky situations lead to the download of the wrong file or the upload of a file to the wrong place. When this happens, the same credentials are used and the server name is the same.
Weakness
The product does not sufficiently enforce boundaries between the states of different sessions, causing data to be provided to, or used by, the wrong session.
Affected Software
| Name | Vendor | Start Version | End Version |
|---|---|---|---|
| Curl | Haxx | 7.40.0 (including) | 8.20.0 (excluding) |
| Red Hat Hardened Images | RedHat | curl-main-8.20.0-0.1.hum1 | * |
| Curl | Ubuntu | esm-infra-legacy/xenial | * |
| Curl | Ubuntu | esm-infra/bionic | * |
| Curl | Ubuntu | esm-infra/focal | * |
| Curl | Ubuntu | esm-infra/xenial | * |
| Curl | Ubuntu | jammy | * |
| Curl | Ubuntu | noble | * |
| Curl | Ubuntu | questing | * |
| Curl | Ubuntu | resolute | * |
| Curl | Ubuntu | upstream | * |
Extended Description
Data can “bleed” from one session to another through member variables of singleton objects, such as Servlets, and objects from a shared pool. In the case of Servlets, developers sometimes do not understand that, unless a Servlet implements the SingleThreadModel interface, the Servlet is a singleton; there is only one instance of the Servlet, and that single instance is used and re-used to handle multiple requests that are processed simultaneously by different threads. A common result is that developers use Servlet member fields in such a way that one user may inadvertently see another user’s data. In other words, storing user data in Servlet member fields introduces a data access race condition.