RHEL 6 : MRG (RHSA-2019:1487) (SACK Panic) (SACK Slowness)

Medium Nessus Plugin ID 126057

Synopsis

The remote Red Hat host is missing one or more security updates.

Description

An update for kernel-rt is now available for Red Hat Enterprise MRG 2.

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.

The kernel-rt packages provide the Real Time Linux Kernel, which enables fine-tuning for systems with extremely high determinism requirements.

Security Fix(es) :

* An integer overflow flaw was found in the way the Linux kernel's networking subsystem processed TCP Selective Acknowledgment (SACK) segments. While processing SACK segments, the Linux kernel's socket buffer (SKB) data structure becomes fragmented. Each fragment is about TCP maximum segment size (MSS) bytes. To efficiently process SACK blocks, the Linux kernel merges multiple fragmented SKBs into one, potentially overflowing the variable holding the number of segments. A remote attacker could use this flaw to crash the Linux kernel by sending a crafted sequence of SACK segments on a TCP connection with small value of TCP MSS, resulting in a denial of service (DoS).
(CVE-2019-11477)

* kernel: race condition in snd_seq_write() may lead to UAF or OOB-access (CVE-2018-7566)

* kernel: Race condition in sound system can lead to denial of service (CVE-2018-1000004)

* Kernel: tcp: excessive resource consumption while processing SACK blocks allows remote denial of service (CVE-2019-11478)

* Kernel: tcp: excessive resource consumption for TCP connections with low MSS allows remote denial of service (CVE-2019-11479)

For more details about the security issue(s), including the impact, a CVSS score, acknowledgments, and other related information, refer to the CVE page(s) listed in the References section.

Bug Fix(es) :

* update the MRG 2.5.z 3.10 kernel-rt sources (BZ#1711010)

Solution

Update the affected packages.

See Also

https://access.redhat.com/security/vulnerabilities/tcpsack

https://access.redhat.com/errata/RHSA-2019:1487

https://access.redhat.com/security/cve/cve-2018-7566

https://access.redhat.com/security/cve/cve-2018-1000004

https://access.redhat.com/security/cve/cve-2019-11477

https://access.redhat.com/security/cve/cve-2019-11478

https://access.redhat.com/security/cve/cve-2019-11479

Plugin Details

Severity: Medium

ID: 126057

File Name: redhat-RHSA-2019-1487.nasl

Version: 1.6

Type: local

Agent: unix

Published: 2019/06/20

Updated: 2020/01/10

Dependencies: 12634, 122878

Risk Information

Risk Factor: Medium

CVSS Score Source: CVE-2018-7566

CVSS v2.0

Base Score: 4.6

Temporal Score: 3.4

Vector: CVSS2#AV:L/AC:L/Au:N/C:P/I:P/A:P

Temporal Vector: CVSS2#E:U/RL:OF/RC:C

CVSS v3.0

Base Score: 7.8

Temporal Score: 6.8

Vector: CVSS:3.0/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Temporal Vector: CVSS:3.0/E:U/RL:O/RC:C

Vulnerability Information

CPE: p-cpe:/a:redhat:enterprise_linux:kernel-rt, p-cpe:/a:redhat:enterprise_linux:kernel-rt-debug, p-cpe:/a:redhat:enterprise_linux:kernel-rt-debug-debuginfo, p-cpe:/a:redhat:enterprise_linux:kernel-rt-debug-devel, p-cpe:/a:redhat:enterprise_linux:kernel-rt-debuginfo, p-cpe:/a:redhat:enterprise_linux:kernel-rt-debuginfo-common-x86_64, p-cpe:/a:redhat:enterprise_linux:kernel-rt-devel, p-cpe:/a:redhat:enterprise_linux:kernel-rt-doc, p-cpe:/a:redhat:enterprise_linux:kernel-rt-firmware, p-cpe:/a:redhat:enterprise_linux:kernel-rt-trace, p-cpe:/a:redhat:enterprise_linux:kernel-rt-trace-debuginfo, p-cpe:/a:redhat:enterprise_linux:kernel-rt-trace-devel, p-cpe:/a:redhat:enterprise_linux:kernel-rt-vanilla, p-cpe:/a:redhat:enterprise_linux:kernel-rt-vanilla-debuginfo, p-cpe:/a:redhat:enterprise_linux:kernel-rt-vanilla-devel, cpe:/o:redhat:enterprise_linux:6

Required KB Items: Host/local_checks_enabled, Host/RedHat/release, Host/RedHat/rpm-list, Host/cpu

Exploit Ease: No known exploits are available

Patch Publication Date: 2019/06/17

Vulnerability Publication Date: 2018/01/16

Reference Information

CVE: CVE-2018-1000004, CVE-2018-7566, CVE-2019-11477, CVE-2019-11478, CVE-2019-11479

RHSA: 2019:1487