Racket is a general-purpose programming language and an ecosystem for language-oriented programming. In versions prior to 8.2, code evaluated using the Racket sandbox could cause system modules to incorrectly use attacker-created modules instead of their intended dependencies. This could allow system functions to be controlled by the attacker, giving access to facilities intended to be restricted. This problem is fixed in Racket version 8.2. A workaround is available, depending on system settings. For systems that provide arbitrary Racket evaluation, external sandboxing such as containers limit the impact of the problem. For multi-user evaluation systems, such as the handin-server system, it is not possible to work around this problem and upgrading is required.
The product receives a request, message, or directive from an upstream component, but the product does not sufficiently preserve the original source of the request before forwarding the request to an external actor that is outside of the product’s control sphere. This causes the product to appear to be the source of the request, leading it to act as a proxy or other intermediary between the upstream component and the external actor.
| Name | Vendor | Start Version | End Version |
|---|---|---|---|
| Racket | Racket-lang | * | 8.2 (excluding) |
| Racket | Ubuntu | bionic | * |
| Racket | Ubuntu | esm-apps/bionic | * |
| Racket | Ubuntu | esm-apps/focal | * |
| Racket | Ubuntu | focal | * |
| Racket | Ubuntu | groovy | * |
| Racket | Ubuntu | hirsute | * |
| Racket | Ubuntu | impish | * |
| Racket | Ubuntu | kinetic | * |
| Racket | Ubuntu | lunar | * |
| Racket | Ubuntu | mantic | * |
| Racket | Ubuntu | trusty | * |
| Racket | Ubuntu | xenial | * |
If an attacker cannot directly contact a target, but the product has access to the target, then the attacker can send a request to the product and have it be forwarded to the target. The request would appear to be coming from the product’s system, not the attacker’s system. As a result, the attacker can bypass access controls (such as firewalls) or hide the source of malicious requests, since the requests would not be coming directly from the attacker. Since proxy functionality and message-forwarding often serve a legitimate purpose, this issue only becomes a vulnerability when: