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Red Hat Enterprise Linux 7: RHSA-2016:1633-01 Important: TCP Attack

red hat
Calendar Grey August 18, 2016
Scroller Redhat
A significant security patch from Red Hat tackles severe networking vulnerabilities affecting Linux platforms.
An update for kernel is now available for Red Hat Enterprise Linux 7

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.

Summary

The kernel packages contain the Linux kernel, the core of any Linux operating system.
It was found that the RFC 5961 challenge ACK rate limiting as implemented in the Linux kernel's networking subsystem allowed an off-path attacker to leak certain information about a given connection by creating congestion on the global challenge ACK rate limit counter and then measuring the changes by probing packets. An off-path attacker could use this flaw to either terminate TCP connection and/or inject payload into non-secured TCP connection between two endpoints on the network. (CVE-2016-5696, Important)
Red Hat would like to thank Yue Cao from Cyber Security Group in the CS department of University of California, Riverside, for reporting this issue.

Topics%20covered

Topics Covered

security advisory Red Hat bug fix kernel important update TCP attack networking flaw

References

https://access.redhat.com/security/cve/CVE-2016-5696 https://access.redhat.com/security/updates/classification/#important

Package List

Red Hat Enterprise Linux Client (v. 7):
Source: kernel-3.10.0-327.28.3.el7.src.rpm
noarch: kernel-abi-whitelists-3.10.0-327.28.3.el7.noarch.rpm kernel-doc-3.10.0-327.28.3.el7.noarch.rpm
x86_64: kernel-3.10.0-327.28.3.el7.x86_64.rpm kernel-debug-3.10.0-327.28.3.el7.x86_64.rpm kernel-debug-debuginfo-3.10.0-327.28.3.el7.x86_64.rpm kernel-debug-devel-3.10.0-327.28.3.el7.x86_64.rpm kernel-debuginfo-3.10.0-327.28.3.el7.x86_64.rpm kernel-debuginfo-common-x86_64-3.10.0-327.28.3.el7.x86_64.rpm kernel-devel-3.10.0-327.28.3.el7.x86_64.rpm kernel-headers-3.10.0-327.28.3.el7.x86_64.rpm kernel-tools-3.10.0-327.28.3.el7.x86_64.rpm kernel-tools-debuginfo-3.10.0-327.28.3.el7.x86_64.rpm kernel-tools-libs-3.10.0-327.28.3.el7.x86_64.rpm perf-3.10.0-327.28.3.el7.x86_64.rpm perf-debuginfo-3.10.0-327.28.3.el7.x86_64.rpm python-perf-3.10.0-327.28.3.el7.x86_64.rpm python-perf-debuginfo-3.10.0-327.28.3.el7.x86_64.rpm
Red Hat Enterprise Linux Client Optional (v. 7):
x86_64: kernel-debug-debuginfo-3.10.0-327.28.3.el7.x86_64.rpm kernel-debuginfo-3.10.0-327.28.3.el7.x86_64.rpm kernel-debuginfo-common-x86_64-3.10.0-327.28.3.el7.x86_64.rpm kernel-tools-debuginfo-3.10.0-327.28.3.el7.x86_64.rpm kernel-tools-libs-devel-3.10.0-327.28.3.el7.x86_64.rpm perf-debuginfo-3.10.0-327.28.3.el7.x86_64.rpm

Read the Full Advisory


Severity
important
Lowest
Low
Medium
High
Critical

Advisory ID: RHSA-2016:1633-01
Product: Red Hat Enterprise Linux
Advisory URL: https://access.redhat.com/errata/RHSA-2016:1633.html
Issue date: 2016-08-18

Topic

An update for kernel is now available for Red Hat Enterprise Linux 7.Red Hat Product Security has rated this update as having a security impactof Important. A Common Vulnerability Scoring System (CVSS) base score,which gives a detailed severity rating, is available for each vulnerabilityfrom the CVE link(s) in the References section.

Topics%20covered

Topics Covered

security advisory Red Hat bug fix kernel important update TCP attack networking flaw

Relevant Releases Architectures

Red Hat Enterprise Linux Client (v. 7) - noarch, x86_64

Red Hat Enterprise Linux Client Optional (v. 7) - x86_64

Red Hat Enterprise Linux ComputeNode (v. 7) - noarch, x86_64

Red Hat Enterprise Linux ComputeNode Optional (v. 7) - x86_64

Red Hat Enterprise Linux Server (v. 7) - noarch, ppc64, ppc64le, s390x, x86_64

Red Hat Enterprise Linux Server Optional (v. 7) - ppc64, ppc64le, x86_64

Red Hat Enterprise Linux Workstation (v. 7) - noarch, x86_64

Red Hat Enterprise Linux Workstation Optional (v. 7) - x86_64

Bugs Fixed

1354708 - CVE-2016-5696 kernel: challenge ACK counter information disclosure.

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