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OpenAdvisories
Unscored Public exploit CVE-2016-5696 EUVD-2016-6639GHSA-26qg-wc7f-8867

net/ipv4/tcp_input.c in the Linux kernel before 4.7 does not properly determine the rate of challenge ACK segments, which makes it easier f…

Published Aug 6, 2016 · Updated Aug 6, 2024 · Assigned by mitre

Package: linux Package: linux Package: linux-lts-vivid Package: linux-lts-xenial Package: linux-raspi2 Package: linux-snapdragon Ecosystem: Debian Ecosystem: Ubuntu

Description

net/ipv4/tcp_input.c in the Linux kernel before 4.7 does not properly determine the rate of challenge ACK segments, which makes it easier for remote attackers to hijack TCP sessions via a blind in-window attack.

Fixed in Linux distributions

Distributions backport fixes, so the version that fixes this vulnerability differs per release — upgrade to at least the version shown. From the distributions' security trackers and advisories.

Debian

Security tracker ↗
ReleasePackageFixed inAdvisory
Debian 14 linux 4.7.2-1 —
Debian 13 linux 4.7.2-1 —
Debian 12 linux 4.7.2-1 —
Debian 8 linux 3.16.36-1+deb8u1 DSA-3659-1
Debian 7 linux 3.2.81-2 DLA-609-1

Ubuntu

Security tracker ↗
ReleasePackageFixed inAdvisory
Ubuntu 16.04 LTS linux 4.4.0-36.55 USN-3070-1
Ubuntu 16.04 LTS linux-raspi2 4.4.0-1021.27 USN-3070-2
Ubuntu 16.04 LTS linux-snapdragon 4.4.0-1024.27 USN-3070-3
Ubuntu 14.04 LTS linux 3.13.0-95.142 USN-3071-1
Ubuntu 14.04 LTS linux-lts-vivid 3.19.0-68.76~14.04.1 —
Ubuntu 14.04 LTS linux-lts-xenial 4.4.0-36.55~14.04.1 USN-3070-4

Red Hat

Security tracker ↗
ReleasePackageFixed inAdvisory
RHEL 7 kernel-rt +10 3.10.0-327.28.3.rt56.235.el7 RHSA-2016:1632
RHEL 7 perf +18 3.10.0-327.28.3.el7 RHSA-2016:1633
RHEL 6 perf +16 2.6.32-642.4.2.el6 RHSA-2016:1664
Show 5 more (older releases, extended support, other products)
ReleasePackageFixed inAdvisory
RHEL 7.1 EUS kernel-kdump +4 3.10.0-229.40.1.el7 RHSA-2016:1657
RHEL 7.1 EUS perf +13 3.10.0-229.40.1.ael7b RHSA-2016:1657
RHEL 6.7 EUS perf +16 2.6.32-573.34.1.el6 RHSA-2016:1815
RHEL 6.6 EUS perf +16 2.6.32-504.52.1.el6 RHSA-2016:1939
RHEL 6.5 AUS perf +10 2.6.32-431.73.2.el6 RHSA-2016:1814
Red Hat MRG 2 kernel-rt +10 1:3.10.0-327.rt56.195.el6rt RHSA-2016:1631

SUSE

Security tracker ↗
ReleasePackageFixed inAdvisory
SLES 12 SP1 kernel-docs 3.12.67-60.64.18.3 SUSE-SU-2016:2912-1
SLES 12 SP1 kernel-xen +4 3.12.67-60.64.18.1 SUSE-SU-2016:2912-1
SLES 12 kernel-ec2 +4 3.12.61-52.66.1 SUSE-SU-2017:0471-1, SUSE-SU-2016:2912-1
SLES 12 kgraft-patch-SLE12_Update_19 1-2.1 SUSE-SU-2017:0471-1
SLES 11 SP4 kernel-docs 3.0.101-88.3 SUSE-SU-2017:0437-1, SUSE-SU-2016:2976-1
SLES 11 SP4 kernel-ec2 +8 3.0.101-88.1 SUSE-SU-2017:0437-1, SUSE-SU-2016:2976-1
SLES 11 SP3 kernel-ec2 +7 3.0.101-0.47.86.1 SUSE-SU-2016:2245-1
Show 10 more (older releases, extended support, other products)
ReleasePackageFixed inAdvisory
SLES for SAP 12 SP1 kernel-xen +3 3.12.67-60.64.18.1 SUSE-SU-2016:2912-1
SLES for SAP 12 kernel-xen +3 3.12.61-52.66.1 SUSE-SU-2017:0471-1
SLES for SAP 12 kgraft-patch-SLE12_Update_19 1-2.1 SUSE-SU-2017:0471-1
SLES for SAP 11 SP4 kernel-ec2 +8 3.0.101-88.1 SUSE-SU-2017:0437-1, SUSE-SU-2016:2976-1
SLE Real Time 12 SP1 kernel-rt +5 3.12.67-60.27.1 SUSE-SU-2016:3304-1
SLE Real Time 11 SP4 kernel-rt +3 3.0.101.rt130-65.1 SUSE-SU-2017:1102-1, SUSE-SU-2016:3069-1
SLE Live Patching 12 kgraft-patch-SLE12-SP1_Update_9 1-6.3 SUSE-SU-2016:2912-1
SUSE OpenStack Cloud 5 kernel-ec2 +6 3.0.101-0.47.86.1 SUSE-SU-2016:2245-1
SUSE Manager Proxy 2.1 kernel-ec2 +6 3.0.101-0.47.86.1 SUSE-SU-2016:2245-1
SUSE Manager 2.1 kernel-ec2 +6 3.0.101-0.47.86.1 SUSE-SU-2016:2245-1
SUSE Linux Enterprise Point of Sale 11 SP3 kernel-ec2 +6 3.0.101-0.47.86.1 SUSE-SU-2016:2245-1

Oracle Linux

ReleasePackageFixed inAdvisory
Oracle Linux 7 dtrace-modules-3.8.13-118.10.2.el6uek 0.4.5-3.el6 ELSA-2016-3595
Oracle Linux 7 dtrace-modules-3.8.13-118.10.2.el7uek 0.4.5-3.el7 ELSA-2016-3595
Oracle Linux 7 dtrace-modules-4.1.12-37.6.3.el6uek 0.5.2-1.el6 ELSA-2016-3594
Oracle Linux 7 dtrace-modules-4.1.12-37.6.3.el7uek 0.5.2-1.el7 ELSA-2016-3594
Oracle Linux 7 kernel-uek +5 3.8.13-118.10.2.el7uek ELSA-2016-3595, ELSA-2016-3594
Oracle Linux 7 perf +11 3.10.0-327.28.3.el7 ELSA-2016-1633

Public exploits

Exploit or proof-of-concept code for this vulnerability is publicly available, which lowers the bar for attackers. Treat it as a reason to patch sooner.

Third-party code, not reviewed by us. Public PoCs are sometimes fake or contain malware. Read the code first and run it only in an isolated lab, against systems you are authorised to test.

GitHub 5 repositories

  • violentshell/rover ★ 102 · Aug 21, 2016

    Proof of Concept code for CVE-2016-5696

  • jduck/challack ★ 76 · Aug 23, 2016

    Proof-of-concept exploit code for CVE-2016-5696

  • Gnoxter/mountain_goat ★ 40 · Aug 20, 2016

    A PoC demonstrating techniques exploiting CVE-2016-5696 Off-Path TCP Exploits: Global Rate Limit Considered Dangerous

  • bplinux/chackd ★ 2 · Aug 26, 2016

    Daemon to randomize tcp_challenge_ack_limit to prevent side channel attacks CVE-2016-5696

  • unkaktus/grill ★ 1 · Dec 7, 2016

    global rate-limiting in Linux (CVE-2016-5696) scanner

Sources: PoC-in-GitHub, Metasploit Framework, Exploit-DB — updated daily. Only links are listed; no exploit code is hosted here.

Advisories 26

References