# CVE-2017-8819: Denial of service in Tor before 0.2.5.16, 0.2.6 through 0.2.8 before 0.2.8.17, 0.2.9 before 0.2.9.14, 0.3.0 before 0.3.0.13, and 0.3.1 before 0.3.1.9

> Attackers can cause denial of service in Tor v2 onion services by sending excessive INTRODUCE2 cells, bypassing replay-cache protections.

- **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:** 3 Dec 2017
- **Updated:** 5 Aug 2024
- **Also known as:** DEBIAN-CVE-2017-8819, GHSA-g7c7-c6jv-wv5p, UBUNTU-CVE-2017-8819

## What is CVE-2017-8819?

CVE-2017-8819 is a high-severity denial of service vulnerability in Debian Debian Linux, published on 3 Dec 2017. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

In Tor before 0.2.5.16, 0.2.6 through 0.2.8 before 0.2.8.17, 0.2.9 before 0.2.9.14, 0.3.0 before 0.3.0.13, and 0.3.1 before 0.3.1.9, the replay-cache protection mechanism is ineffective for v2 onion services, aka TROVE-2017-009. An attacker can send many INTRODUCE2 cells to trigger this issue.

## Which versions are affected by CVE-2017-8819?

It affects 2 products.


Products: Debian Debian Linux, Tor Project Tor.

## How do I fix CVE-2017-8819?

Upgrade to a fixed version.

## Is CVE-2017-8819 being exploited?

There is no known exploitation of CVE-2017-8819 in the wild and no public exploit code.

## Other vulnerabilities in Debian Debian Linux

- [CVE-2015-3306](https://insights.sbomify.com/CVE-2015-3306/): ProFTPD Improper Access Control (critical 10.0, exploited in the wild)
- [CVE-2025-49113](https://insights.sbomify.com/CVE-2025-49113/): RoundCube Webmail Deserialization of Untrusted Data (critical 9.9, exploited in the wild)
- [CVE-2026-24061](https://insights.sbomify.com/CVE-2026-24061/): GNU InetUtils Argument Injection (critical 9.8, exploited in the wild)
- [CVE-2025-39682](https://insights.sbomify.com/CVE-2025-39682/): Linux Kernel Improper Check for Unusual or Exceptional Conditions (critical 9.8, exploited in the wild)
- [CVE-2024-9680](https://insights.sbomify.com/CVE-2024-9680/): Mozilla Firefox Use-After-Free (critical 9.8, exploited in the wild)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2017-8819 and fix it if it is affected.

What it is: CVE-2017-8819 is a high-severity denial of service vulnerability in Debian Debian Linux, published on 3 Dec 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-2017-8819 in the wild and no public exploit code.

Affected product: Debian Debian Linux. 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-2017-8819/ (Markdown: https://insights.sbomify.com/CVE-2017-8819/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2017-8819
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2017-8819
- OSV: https://osv.dev/vulnerability/CVE-2017-8819

---
From sbomify Insights: https://insights.sbomify.com/CVE-2017-8819/
Summaries are generated and may contain mistakes; the official description above is the record.