CVE-2017-17805: Canonical Ubuntu Linux

High severity, CVSS 7.8. EPSS: 0.4% chance of exploitation in the next 30 days.

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.

Affected products

• Canonical Ubuntu Linux: version 12.04 only; version 14.04 only; version 16.04 only; version 17.10 only
• Debian Debian Linux: version 8.0 only; version 9.0 only
• Linux Linux Kernel: from 2.6.25, before 3.2.97 (fixed in 3.2.97); from 3.3, before 3.16.52 (fixed in 3.16.52); from 3.17, before 3.18.89 (fixed in 3.18.89); from 3.19, before 4.1.49 (fixed in 4.1.49); from 4.2, before 4.4.107 (fixed in 4.4.107); from 4.5, before 4.9.71 (fixed in 4.9.71); …
• Opensuse Leap: version 42.2 only
• Opensuse Project Leap: version 42.3 only
• Suse Linux Enterprise Desktop: version 12 only
• Suse Linux Enterprise Server: version 11 only; version 12 only
• Suse Linux Enterprise Server For Raspberry Pi: version 12 only

Published 2017-12-20. Last modified 2026-06-17.