CVE-2017-17805 Denial of service in n/a
A local attacker can cause a kernel crash and denial of service by exploiting a zero-length input handling flaw in the Salsa20 encryption algorithm.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2017-17805?
CVE-2017-17805 is a high-severity denial of service vulnerability in Canonical Ubuntu Linux, published on 20 Dec 2017. It can only be exploited from the same machine or local network, with no action from the victim.
Official description
The Salsa20 encryption algorithm in the Linux kernel before 4.14.8 does not correctly handle zero-length inputs, allowing a local attacker able to use the AF_ALG-based skcipher interface (CONFIG_CRYPTO_USER_API_SKCIPHER) to cause a denial of service (uninitialized-memory free and kernel crash) or have unspecified other impact by executing a crafted sequence of system calls that use the blkcipher_walk API. Both the generic implementation (crypto/salsa20_generic.c) and x86 implementation (arch/x86/crypto/salsa20_glue.c) of Salsa20 were vulnerable.
Weakness: CWE-20
Which versions are affected by CVE-2017-17805?
It affects 8 products.
Products include Canonical Ubuntu Linux, Debian Debian Linux, Linux kernel, Opensuse Leap, Opensuse Project Leap, Suse Linux Enterprise Desktop and 2 more.
How do I fix CVE-2017-17805?
Apply the vendor's patch.
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-2017-17805 being exploited?
There is no known exploitation of CVE-2017-17805 in the wild and no public exploit code.
Other vulnerabilities in Canonical Ubuntu Linux
Sources
Also known as DEBIAN-CVE-2017-17805, GHSA-h6gr-h9qh-f94v, UBUNTU-CVE-2017-17805.