Report suspected vulnerabilities through GitHub's private vulnerability reporting. Please do not open a public issue for anything exploitable.

Include what you did, what happened, and what you expected. A reproducer — a server response, a server list, a command line — is worth more than a description. Expect a first reply within a week.

It is a speed test client, so it talks to servers it does not control, and it is often run unattended from a router. The threat model follows from that.

Everything a speed test server sends. The server list, its entries, and every response from a backend are attacker-influenced: --server-json takes a URL from the user, and the list it returns names further hosts. Accordingly:

• Buffered responses are capped (8 MiB for the server list and control endpoints, 64 KiB for telemetry). Transfer bodies are streamed and never buffered. Server lists read from a file or stdin are capped the same way.
• Server names, sponsor strings and the getIP response are stripped of C0, DEL and C1 control characters before display, so a server cannot drive the terminal with escape sequences or forge an extra --list entry with an embedded newline.
• CSV fields that come from a server are prefixed with ' when they start with =, +, -, @, TAB or CR, so opening a report in a spreadsheet cannot execute a formula.
• Redirects may not downgrade https to http, and a 307/308 that would replay a POST body to a different origin is refused — the telemetry POST carries the measurement, the client's IP and ISP details.

Command line values. Numeric options are bounded at parse time, so no input can drive an allocation or a test duration out of range.

The user. --server-json, --local-json, --ca-cert and --source all do what they say, including reaching hosts on the local network. If you wrap this program in a service that passes user input to --server-json, you have built an SSRF primitive; validate the URL yourself.

The system trust store, unless you override it with --ca-cert or disable verification with --skip-cert-verify. The latter accepts any certificate and makes the connection trivially interceptable; it exists for self-signed test backends and should not be used against anything else.

No telemetry is sent unless you ask for it. --share, --telemetry-level and the other --telemetry-* options upload your measurement, your public IP and your ISP details to a telemetry server — by default librespeed.org, or whichever server you point them at — and return a public link to the result.

The latest release. Fixes are not backported.

CI runs cargo audit against the RustSec database on every dependency change and weekly, and cargo deny for advisories, licences, sources and duplicate crates. Dependabot proposes updates for cargo and GitHub Actions.