Synopsis
Important: kernel security update
Type/Severity
Security Advisory: Important
Topic
An update for kernel is now available for Red Hat Enterprise Linux 6.7 Extended Update Support.
Red Hat Product Security has rated this update as having a security impact of Important. A Common Vulnerability Scoring System (CVSS) base score, which gives a detailed severity rating, is available for each vulnerability from the CVE link(s) in the References section.
Description
The kernel packages contain the Linux kernel, the core of any Linux operating system.
Security Fix(es):
- A flaw named SegmentSmack was found in the way the Linux kernel handled specially crafted TCP packets. A remote attacker could use this flaw to trigger time and calculation expensive calls to tcp_collapse_ofo_queue() and tcp_prune_ofo_queue() functions by sending specially modified packets within ongoing TCP sessions which could lead to a CPU saturation and hence a denial of service on the system. 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. (CVE-2018-5390)
Red Hat would like to thank Juha-Matti Tilli (Aalto University, Department of Communications and Networking and Nokia Bell Labs) for reporting this issue.
Solution
For details on how to apply this update, which includes the changes described in this advisory, refer to:
https://access.redhat.com/articles/11258
The system must be rebooted for this update to take effect.
Affected Products
-
Red Hat Enterprise Linux Server - Extended Update Support 6.7 x86_64
-
Red Hat Enterprise Linux Server - Extended Update Support 6.7 i386
-
Red Hat Enterprise Linux for IBM z Systems - Extended Update Support 6.7 s390x
-
Red Hat Enterprise Linux for Power, big endian - Extended Update Support 6.7 ppc64
-
Red Hat Enterprise Linux EUS Compute Node 6.7 x86_64
-
RHEL for SAP HANA - Extended Update Support 6.7 x86_64
Fixes
- BZ - 1601704 - CVE-2018-5390 kernel: TCP segments with random offsets allow a remote denial of service (SegmentSmack)
CVEs
References
Vulmon