Cargo is a package manager for the rust programming language. It was discovered that Cargo did not limit the amount of data extracted from compressed archives. An attacker could upload to an alternate registry a specially crafted package that extracts way more data than its size (also known as a zip bomb), exhausting the disk space on the machine using Cargo to download the package. Note that by design Cargo allows code execution at build time, due to build scripts and procedural macros. The vulnerabilities in this advisory allow performing a subset of the possible damage in a harder to track down way. Your dependencies must still be trusted if you want to be protected from attacks, as its possible to perform the same attacks with build scripts and procedural macros. The vulnerability is present in all versions of Cargo. Rust 1.64, to be released on September 22nd, will include a fix for it. Since the vulnerability is just a more limited way to accomplish what a malicious build scripts or procedural macros can do, we decided not to publish Rust point releases backporting the security fix. Patch files are available for Rust 1.63.0 are available in the wg-security-response repository for people building their own toolchain. We recommend users of alternate registries to excercise care in which package they download, by only including trusted dependencies in their projects. Please note that even with these vulnerabilities fixed, by design Cargo allows arbitrary code execution at build time thanks to build scripts and procedural macros: a malicious dependency will be able to cause damage regardless of these vulnerabilities. crates.io implemented server-side checks to reject these kinds of packages years ago, and there are no packages on crates.io exploiting these vulnerabilities. crates.io users still need to excercise care in choosing their dependencies though, as the same concerns about build scripts and procedural macros apply here.
The product does not properly control the allocation and maintenance of a limited resource, thereby enabling an actor to influence the amount of resources consumed, eventually leading to the exhaustion of available resources.
| Name | Vendor | Start Version | End Version |
|---|---|---|---|
| Cargo | Rust-lang | * | 0.65.0 (excluding) |
Limited resources include memory, file system storage, database connection pool entries, and CPU. If an attacker can trigger the allocation of these limited resources, but the number or size of the resources is not controlled, then the attacker could cause a denial of service that consumes all available resources. This would prevent valid users from accessing the product, and it could potentially have an impact on the surrounding environment. For example, a memory exhaustion attack against an application could slow down the application as well as its host operating system. There are at least three distinct scenarios which can commonly lead to resource exhaustion:
Resource exhaustion problems are often result due to an incorrect implementation of the following situations:
Mitigation of resource exhaustion attacks requires that the target system either:
The first of these solutions is an issue in itself though, since it may allow attackers to prevent the use of the system by a particular valid user. If the attacker impersonates the valid user, they may be able to prevent the user from accessing the server in question.
The second solution is simply difficult to effectively institute – and even when properly done, it does not provide a full solution. It simply makes the attack require more resources on the part of the attacker.