CVE-2016-5696

Published: 06 August 2016

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.

From the Ubuntu security team

Yue Cao et al discovered a flaw in the TCP implementation's handling of challenge acks in the Linux kernel. A remote attacker could use this to cause a denial of service (reset connection) or inject content into an TCP stream.

Priority

Medium

CVSS 3 base score: 4.8

Status

Package Release Status
linux
Launchpad, Ubuntu, Debian
Upstream
Released (4.7)
Ubuntu 16.04 ESM (Xenial Xerus)
Released (4.4.0-36.55)
Ubuntu 14.04 ESM (Trusty Tahr)
Released (3.13.0-95.142)
Patches:
Introduced by 282f23c6ee343126156dd41218b22ece96d747e3
Fixed by 75ff39ccc1bd5d3c455b6822ab09e533c551f758
linux-armadaxp
Launchpad, Ubuntu, Debian
Upstream
Released (4.7)
Ubuntu 16.04 ESM (Xenial Xerus) Does not exist

Ubuntu 14.04 ESM (Trusty Tahr) Does not exist

This package is not directly supported by the Ubuntu Security Team
linux-aws
Launchpad, Ubuntu, Debian
Upstream
Released (4.7)
Ubuntu 16.04 ESM (Xenial Xerus) Not vulnerable
(4.4.0-1001.10)
Ubuntu 14.04 ESM (Trusty Tahr) Not vulnerable
(4.4.0-1002.2)
linux-flo
Launchpad, Ubuntu, Debian
Upstream
Released (4.7)
Ubuntu 16.04 ESM (Xenial Xerus) Not vulnerable

Ubuntu 14.04 ESM (Trusty Tahr) Does not exist
(trusty was ignored)
linux-gke
Launchpad, Ubuntu, Debian
Upstream
Released (4.7)
Ubuntu 16.04 ESM (Xenial Xerus) Not vulnerable
(4.4.0-1003.3)
Ubuntu 14.04 ESM (Trusty Tahr) Does not exist

linux-goldfish
Launchpad, Ubuntu, Debian
Upstream
Released (4.7)
Ubuntu 16.04 ESM (Xenial Xerus) Ignored
(abandoned)
Ubuntu 14.04 ESM (Trusty Tahr) Does not exist
(trusty was ignored)
linux-grouper
Launchpad, Ubuntu, Debian
Upstream
Released (4.7)
Ubuntu 16.04 ESM (Xenial Xerus) Does not exist

Ubuntu 14.04 ESM (Trusty Tahr) Does not exist
(trusty was ignored)
linux-hwe
Launchpad, Ubuntu, Debian
Upstream
Released (4.7)
Ubuntu 16.04 ESM (Xenial Xerus) Not vulnerable
(4.8.0-36.36~16.04.1)
Ubuntu 14.04 ESM (Trusty Tahr) Does not exist

linux-hwe-edge
Launchpad, Ubuntu, Debian
Upstream
Released (4.7)
Ubuntu 16.04 ESM (Xenial Xerus) Not vulnerable
(4.8.0-36.36~16.04.1)
Ubuntu 14.04 ESM (Trusty Tahr) Does not exist

linux-linaro-omap
Launchpad, Ubuntu, Debian
Upstream
Released (4.7)
Ubuntu 16.04 ESM (Xenial Xerus) Does not exist

Ubuntu 14.04 ESM (Trusty Tahr) Does not exist

linux-linaro-shared
Launchpad, Ubuntu, Debian
Upstream
Released (4.7)
Ubuntu 16.04 ESM (Xenial Xerus) Does not exist

Ubuntu 14.04 ESM (Trusty Tahr) Does not exist

linux-linaro-vexpress
Launchpad, Ubuntu, Debian
Upstream
Released (4.7)
Ubuntu 16.04 ESM (Xenial Xerus) Does not exist

Ubuntu 14.04 ESM (Trusty Tahr) Does not exist

linux-lts-quantal
Launchpad, Ubuntu, Debian
Upstream
Released (4.7)
Ubuntu 16.04 ESM (Xenial Xerus) Does not exist

Ubuntu 14.04 ESM (Trusty Tahr) Does not exist

This package is not directly supported by the Ubuntu Security Team
linux-lts-raring
Launchpad, Ubuntu, Debian
Upstream
Released (4.7)
Ubuntu 16.04 ESM (Xenial Xerus) Does not exist

Ubuntu 14.04 ESM (Trusty Tahr) Does not exist

linux-lts-saucy
Launchpad, Ubuntu, Debian
Upstream
Released (4.7)
Ubuntu 16.04 ESM (Xenial Xerus) Does not exist

Ubuntu 14.04 ESM (Trusty Tahr) Does not exist

This package is not directly supported by the Ubuntu Security Team
linux-lts-trusty
Launchpad, Ubuntu, Debian
Upstream
Released (4.7)
Ubuntu 16.04 ESM (Xenial Xerus) Does not exist

Ubuntu 14.04 ESM (Trusty Tahr) Does not exist

linux-lts-utopic
Launchpad, Ubuntu, Debian
Upstream
Released (4.7)
Ubuntu 16.04 ESM (Xenial Xerus) Does not exist

Ubuntu 14.04 ESM (Trusty Tahr) Does not exist
(trusty was ignored [out of standard support])
linux-lts-vivid
Launchpad, Ubuntu, Debian
Upstream
Released (4.7)
Ubuntu 16.04 ESM (Xenial Xerus) Does not exist

Ubuntu 14.04 ESM (Trusty Tahr) Does not exist
(trusty was released [3.19.0-68.76~14.04.1])
linux-lts-wily
Launchpad, Ubuntu, Debian
Upstream
Released (4.7)
Ubuntu 16.04 ESM (Xenial Xerus) Does not exist

Ubuntu 14.04 ESM (Trusty Tahr) Does not exist
(trusty was ignored [out of standard support])
linux-lts-xenial
Launchpad, Ubuntu, Debian
Upstream
Released (4.7)
Ubuntu 16.04 ESM (Xenial Xerus) Does not exist

Ubuntu 14.04 ESM (Trusty Tahr)
Released (4.4.0-36.55~14.04.1)
linux-maguro
Launchpad, Ubuntu, Debian
Upstream
Released (4.7)
Ubuntu 16.04 ESM (Xenial Xerus) Does not exist

Ubuntu 14.04 ESM (Trusty Tahr) Does not exist
(trusty was ignored)
linux-mako
Launchpad, Ubuntu, Debian
Upstream
Released (4.7)
Ubuntu 16.04 ESM (Xenial Xerus) Not vulnerable

Ubuntu 14.04 ESM (Trusty Tahr) Does not exist
(trusty was ignored)
linux-manta
Launchpad, Ubuntu, Debian
Upstream
Released (4.7)
Ubuntu 16.04 ESM (Xenial Xerus) Does not exist

Ubuntu 14.04 ESM (Trusty Tahr) Does not exist
(trusty was ignored)
linux-qcm-msm
Launchpad, Ubuntu, Debian
Upstream
Released (4.7)
Ubuntu 16.04 ESM (Xenial Xerus) Does not exist

Ubuntu 14.04 ESM (Trusty Tahr) Does not exist

linux-raspi2
Launchpad, Ubuntu, Debian
Upstream
Released (4.7)
Ubuntu 16.04 ESM (Xenial Xerus)
Released (4.4.0-1021.27)
Ubuntu 14.04 ESM (Trusty Tahr) Does not exist

linux-snapdragon
Launchpad, Ubuntu, Debian
Upstream
Released (4.7)
Ubuntu 16.04 ESM (Xenial Xerus)
Released (4.4.0-1024.27)
Ubuntu 14.04 ESM (Trusty Tahr) Does not exist

linux-ti-omap4
Launchpad, Ubuntu, Debian
Upstream
Released (4.7)
Ubuntu 16.04 ESM (Xenial Xerus) Does not exist

Ubuntu 14.04 ESM (Trusty Tahr) Does not exist

Notes

AuthorNote
jdstrand
android kernels (flo, goldfish, grouper, maguro, mako and manta) are
not supported on the Ubuntu Touch 14.10 and earlier preview kernels
linux-lts-saucy no longer receives official support
linux-lts-quantal no longer receives official support
sbeattie
fix is going to land in Ubuntu kernels in this SRU cycle,
with a likely release date of Aug 27. Earlier access to the kernels
with the fix will be available from the -proposed pocket, though they
come with the risk of being less tested.

References

Bugs