--- title: "CVE-2017-8819\n | Ubuntu" description: Ubuntu is an open source software operating system that runs from the desktop, to the cloud, to all your internet connected things. url: https://ubuntu.com/security/CVE-2017-8819?format=md keywords: index, follow --- # CVE-2017-8819 Publication date 3 December 2017 Last updated 25 August 2025 --- Ubuntu priority **Medium** [Why this priority?](https://ubuntu.com/security/cves/about#priority ) ## Cvss 3 Severity Score **7.5 · High** [Score breakdown](https://ubuntu.com/security/CVE-2017-8819?format=md#impact-score) Toggle side navigation ## 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. ### From the Ubuntu Security Team It was discovered that the replay-cache protection mechanism used by Tor is ineffective for v2 onion services. An attacker could possible use this to facilitate a traffic confirmation attack. ## Status Show unmaintained releases | Package | Ubuntu Release | Status | | --- | --- | --- | | tor | 18.10 cosmic | Not affected | | 18.04 LTS bionic | Not affected | | 17.10 artful | Fixed 0.3.0.13-0ubuntu1~17.10.2 | | 17.04 zesty | Ignored end of life | | 16.04 LTS xenial | Fixed 0.2.9.14-1ubuntu1~16.04.2 | | 14.04 LTS trusty | Fixed 0.2.4.27-1ubuntu0.1 | --- * [How can I get the fixes?](https://ubuntu.com/security/cves/about#security) * [What do statuses mean?](https://ubuntu.com/security/cves/about#statuses) ## Severity score breakdown CVSS version: CVSS v3.0 **Base score** 7.5 · High * Base metrics | Parameter | Value | | --- | --- | | Attack vector | Network | | Attack complexity | Low | | Privileges required | None | | User interaction | None | | Scope | Unchanged | | Confidentiality impact | None | | Integrity impact | None | | Availability impact | High | * Scores | Parameter | Value | | --- | --- | | Base score | 7.5 · High | | Exploitability score | - | | Impact score | - | **Vector:** CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H ## References * [MITRE](https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2017-8819) * [NVD](https://nvd.nist.gov/vuln/detail/CVE-2017-8819) * [Launchpad](https://launchpad.net/bugs/cve/CVE-2017-8819) * [Debian](https://security-tracker.debian.org/tracker/CVE-2017-8819) ### Other references * * *