# CVE-2017-0375: Denial of service in Tor before 0.3.0.8

> A remote attacker can cause a denial of service in Tor hidden services by sending a malformed BEGIN cell, crashing the daemon.

- **Severity:** High 7.5 (`CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 9 Jun 2017
- **Updated:** 5 Aug 2024
- **Also known as:** GHSA-2mmr-2hq6-5c3v

## What is CVE-2017-0375?

CVE-2017-0375 is a high-severity denial of service vulnerability in Tor before 0.3.0.8, published on 9 Jun 2017. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

The hidden-service feature in Tor before 0.3.0.8 allows a denial of service (assertion failure and daemon exit) in the relay_send_end_cell_from_edge_ function via a malformed BEGIN cell.

Weakness: CWE-617 (Reachable Assertion)

## Which versions are affected by CVE-2017-0375?

It affects 1 product.


Products: Torproject Tor.

## How do I fix CVE-2017-0375?

Upgrade to a fixed version.

## Is CVE-2017-0375 being exploited?

There is no known exploitation of CVE-2017-0375 in the wild and no public exploit code.

## Other vulnerabilities in Tor before 0.3.0.8

- [CVE-2026-77638](https://insights.sbomify.com/CVE-2026-77638/): Race condition in Tor (high 8.9)
- [CVE-2026-77642](https://insights.sbomify.com/CVE-2026-77642/): Memory corruption in Tor (high 7.5)
- [CVE-2022-33903](https://insights.sbomify.com/CVE-2022-33903/): Denial of service in n/a (high 7.5)
- [CVE-2021-38385](https://insights.sbomify.com/CVE-2021-38385/): Denial of service in n/a (high 7.5)
- [CVE-2021-34548](https://insights.sbomify.com/CVE-2021-34548/): Security feature bypass in n/a (high 7.5)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2017-0375 and fix it if it is affected.

What it is: CVE-2017-0375 is a high-severity denial of service vulnerability in Tor before 0.3.0.8, published on 9 Jun 2017. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2017-0375 in the wild and no public exploit code.

Affected product: Tor before 0.3.0.8. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2017-0375/ (Markdown: https://insights.sbomify.com/CVE-2017-0375/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2017-0375
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2017-0375
- OSV: https://osv.dev/vulnerability/CVE-2017-0375

---
From sbomify Insights: https://insights.sbomify.com/CVE-2017-0375/
Summaries are generated and may contain mistakes; the official description above is the record.