Synology-SA-18:44 Linux kernel

Abstract

CVE-2018-5391, a.k.a. FragmentSmack attack, allows remote attackers to conduct denial-of-service attacks via a susceptible version of Synology Diskstation Manager (DSM), SkyNAS or VS960HD.

SRM 1.1 is not affected as CVE-2018-5391 only affects Linux kernel 3.9 or above.

Affected Products

Mitigation

If you need immediate assistance, please contact Synology technical support via https://account.synology.com/en-global/support.

Detail

• CVE-2018-5391
  • Severity: Important
  • CVSS3 Base Score: 7.5
  • CVSS3 Vector: CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
  • The Linux kernel, versions 3.9+, is vulnerable to a denial of service attack with low rates of specially modified packets targeting IP fragment re-assembly. An attacker may cause a denial of service condition by sending specially crafted IP fragments. Various vulnerabilities in IP fragmentation have been discovered and fixed over the years. The current vulnerability (CVE-2018-5391) became exploitable in the Linux kernel with the increase of the IP fragment reassembly queue size.

Reference

• CVE-2018-5391
• Linux IP Implementation Vulnerable to DoS attack

Revision