CVE-2017-8821 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
An attacker can cause a denial of service in Tor by providing crafted PEM input that triggers an interactive password prompt, hanging the application.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2017-8821?
CVE-2017-8821 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, an attacker can cause a denial of service (application hang) via crafted PEM input that signifies a public key requiring a password, which triggers an attempt by the OpenSSL library to ask the user for the password, aka TROVE-2017-011.
Weakness: CWE-119
Which versions are affected by CVE-2017-8821?
It affects 2 products.
Products include Debian Debian Linux, Tor Project Tor.
How do I fix CVE-2017-8821?
Upgrade to a fixed version.
Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.
Is CVE-2017-8821 being exploited?
There is no known exploitation of CVE-2017-8821 in the wild and no public exploit code.
Other vulnerabilities in Debian Debian Linux
Sources
Also known as DEBIAN-CVE-2017-8821, GHSA-8p62-7f73-7q9x, UBUNTU-CVE-2017-8821.