Amazon Linux 2 Security Advisory: ALAS-2018-1050
Advisory Release Date: 2018-08-04 23:49 Pacific
Advisory Updated Date: 2018-08-06 19:11 Pacific
Linux kernel versions 4.9+ can be forced to make very expensive calls to tcp_collapse_ofo_queue() and tcp_prune_ofo_queue() for every incoming packet which can lead to a denial of service. An attacker can induce a denial of service condition by sending specially modified packets within ongoing TCP sessions. Maintaining the denial of service condition requires continuous two-way TCP sessions to a reachable open port. Thus, the attacks cannot be performed using spoofed IP addresses. (https://www.kb.cert.org/vuls/id/962459)
Affected Packages:
kernel
Note:
This advisory is applicable to Amazon Linux 2 (AL2) Core repository. Visit this FAQ section for the difference between AL2 Core and AL2 Extras advisories.
Issue Correction:
Run yum update kernel and reboot your instance to update your system.
src:
kernel-4.14.59-68.43.amzn2.src
x86_64:
kernel-4.14.59-68.43.amzn2.x86_64
kernel-headers-4.14.59-68.43.amzn2.x86_64
kernel-debuginfo-common-x86_64-4.14.59-68.43.amzn2.x86_64
perf-4.14.59-68.43.amzn2.x86_64
perf-debuginfo-4.14.59-68.43.amzn2.x86_64
python-perf-4.14.59-68.43.amzn2.x86_64
python-perf-debuginfo-4.14.59-68.43.amzn2.x86_64
kernel-tools-4.14.59-68.43.amzn2.x86_64
kernel-tools-devel-4.14.59-68.43.amzn2.x86_64
kernel-tools-debuginfo-4.14.59-68.43.amzn2.x86_64
kernel-devel-4.14.59-68.43.amzn2.x86_64
kernel-debuginfo-4.14.59-68.43.amzn2.x86_64