CVE-2016-9604

Published: 31 December 2016

It was discovered in the Linux kernel before 4.11-rc8 that root can gain direct access to an internal keyring, such as '.dns_resolver' in RHEL-7 or '.builtin_trusted_keys' upstream, by joining it as its session keyring. This allows root to bypass module signature verification by adding a new public key of its own devising to the keyring.

From the Ubuntu Security Team

It was discovered that the keyring implementation in the Linux kernel in some situations did not prevent special internal keyrings from being joined by userspace keyrings. A privileged local attacker could use this to bypass module verification.

Notes

Author	Note
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

Author

Note

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

Priority

Cvss 3 Severity Score

4.4

Score breakdown

Status

Package	Release	Status
linux Launchpad, Ubuntu, Debian	artful	Not vulnerable (4.10.0-22.24)
	precise	Ignored (was needed ESM criteria)
	trusty	Released (3.13.0-132.181)
	upstream	Released (4.11~rc8)
	xenial	Released (4.4.0-79.100)
	yakkety	Ignored (reached end-of-life)
	zesty	Released (4.10.0-22.24)
	Patches: Introduced by 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 Fixed by ee8f844e3c5a73b999edf733df1c529d6503ec2f
linux-armadaxp Launchpad, Ubuntu, Debian	artful	Does not exist
	precise	Does not exist (precise was needed)
	trusty	Does not exist
	upstream	Released (4.11~rc8)
	xenial	Does not exist
	yakkety	Does not exist
	zesty	Does not exist
	This package is not directly supported by the Ubuntu Security Team
linux-aws Launchpad, Ubuntu, Debian	artful	Does not exist
	precise	Does not exist
	trusty	Not vulnerable (4.4.0-1002.2)
	upstream	Released (4.11~rc8)
	xenial	Released (4.4.0-1018.27)
	yakkety	Does not exist
	zesty	Does not exist
linux-azure Launchpad, Ubuntu, Debian	artful	Does not exist
	precise	Does not exist
	trusty	Not vulnerable (4.15.0-1023.24~14.04.1)
	upstream	Released (4.11~rc8)
	xenial	Not vulnerable (4.11.0-1009.9)
	yakkety	Does not exist
	zesty	Does not exist
linux-euclid Launchpad, Ubuntu, Debian	artful	Does not exist
	precise	Does not exist
	trusty	Does not exist
	upstream	Released (4.11~rc8)
	xenial	Ignored (was needed ESM criteria)
	zesty	Does not exist
linux-flo Launchpad, Ubuntu, Debian	artful	Does not exist
	precise	Does not exist
	trusty	Does not exist (trusty was ignored)
	upstream	Released (4.11~rc8)
	xenial	Ignored (abandoned)
	yakkety	Ignored (abandoned)
	zesty	Does not exist
linux-gcp Launchpad, Ubuntu, Debian	artful	Does not exist
	precise	Does not exist
	trusty	Does not exist
	upstream	Released (4.11~rc8)
	xenial	Not vulnerable (4.10.0-1004.4)
	yakkety	Does not exist
	zesty	Does not exist
linux-gke Launchpad, Ubuntu, Debian	artful	Does not exist
	precise	Does not exist
	trusty	Does not exist
	upstream	Released (4.11~rc8)
	xenial	Released (4.4.0-1014.14)
	yakkety	Does not exist
	zesty	Does not exist
linux-goldfish Launchpad, Ubuntu, Debian	artful	Does not exist
	precise	Does not exist
	trusty	Does not exist (trusty was ignored)
	upstream	Released (4.11~rc8)
	xenial	Ignored (abandoned)
	yakkety	Ignored (abandoned)
	zesty	Ignored (abandoned)
linux-grouper Launchpad, Ubuntu, Debian	artful	Does not exist
	precise	Does not exist
	trusty	Does not exist (trusty was ignored)
	upstream	Released (4.11~rc8)
	xenial	Does not exist
	yakkety	Does not exist
	zesty	Does not exist
linux-hwe Launchpad, Ubuntu, Debian	artful	Does not exist
	precise	Does not exist
	trusty	Does not exist
	upstream	Released (4.11~rc8)
	xenial	Released (4.10.0-27.30~16.04.2)
	yakkety	Does not exist
	zesty	Does not exist
linux-hwe-edge Launchpad, Ubuntu, Debian	artful	Does not exist
	precise	Does not exist
	trusty	Does not exist
	upstream	Released (4.11~rc8)
	xenial	Released (4.10.0-27.30~16.04.2)
	yakkety	Does not exist
	zesty	Does not exist
linux-kvm Launchpad, Ubuntu, Debian	artful	Does not exist
	precise	Does not exist
	trusty	Does not exist
	upstream	Released (4.11~rc8)
	xenial	Not vulnerable (4.4.0-1004.9)
	zesty	Does not exist
linux-linaro-omap Launchpad, Ubuntu, Debian	artful	Does not exist
	precise	Does not exist (precise was ignored [abandoned])
	trusty	Does not exist
	upstream	Released (4.11~rc8)
	xenial	Does not exist
	yakkety	Does not exist
	zesty	Does not exist
linux-linaro-shared Launchpad, Ubuntu, Debian	artful	Does not exist
	precise	Does not exist (precise was ignored [abandoned])
	trusty	Does not exist
	upstream	Released (4.11~rc8)
	xenial	Does not exist
	yakkety	Does not exist
	zesty	Does not exist
linux-linaro-vexpress Launchpad, Ubuntu, Debian	artful	Does not exist
	precise	Does not exist (precise was ignored [abandoned])
	trusty	Does not exist
	upstream	Released (4.11~rc8)
	xenial	Does not exist
	yakkety	Does not exist
	zesty	Does not exist
linux-lts-quantal Launchpad, Ubuntu, Debian	artful	Does not exist
	precise	Does not exist (precise was ignored [end-of-life])
	trusty	Does not exist
	upstream	Released (4.11~rc8)
	xenial	Does not exist
	yakkety	Does not exist
	zesty	Does not exist
	This package is not directly supported by the Ubuntu Security Team
linux-lts-raring Launchpad, Ubuntu, Debian	artful	Does not exist
	precise	Does not exist (precise was ignored [end-of-life])
	trusty	Does not exist
	upstream	Released (4.11~rc8)
	xenial	Does not exist
	yakkety	Does not exist
	zesty	Does not exist
linux-lts-saucy Launchpad, Ubuntu, Debian	artful	Does not exist
	precise	Does not exist (precise was ignored [end-of-life])
	trusty	Does not exist
	upstream	Released (4.11~rc8)
	xenial	Does not exist
	yakkety	Does not exist
	zesty	Does not exist
	This package is not directly supported by the Ubuntu Security Team
linux-lts-trusty Launchpad, Ubuntu, Debian	artful	Does not exist
	precise	Released (3.13.0-132.181~precise1)
	trusty	Does not exist
	upstream	Released (4.11~rc8)
	xenial	Does not exist
	yakkety	Does not exist
	zesty	Does not exist
linux-lts-utopic Launchpad, Ubuntu, Debian	artful	Does not exist
	precise	Does not exist
	trusty	Does not exist (trusty was ignored [out of standard support])
	upstream	Released (4.11~rc8)
	xenial	Does not exist
	yakkety	Does not exist
	zesty	Does not exist
linux-lts-vivid Launchpad, Ubuntu, Debian	artful	Does not exist
	precise	Does not exist
	trusty	Does not exist (trusty was ignored [was needed now end-of-life])
	upstream	Released (4.11~rc8)
	xenial	Does not exist
	yakkety	Does not exist
	zesty	Does not exist
linux-lts-wily Launchpad, Ubuntu, Debian	artful	Does not exist
	precise	Does not exist
	trusty	Does not exist (trusty was ignored [out of standard support])
	upstream	Released (4.11~rc8)
	xenial	Does not exist
	yakkety	Does not exist
	zesty	Does not exist
linux-lts-xenial Launchpad, Ubuntu, Debian	artful	Does not exist
	precise	Does not exist
	trusty	Released (4.4.0-79.100~14.04.1)
	upstream	Released (4.11~rc8)
	xenial	Does not exist
	yakkety	Does not exist
	zesty	Does not exist
linux-maguro Launchpad, Ubuntu, Debian	artful	Does not exist
	precise	Does not exist
	trusty	Does not exist (trusty was ignored)
	upstream	Released (4.11~rc8)
	xenial	Does not exist
	yakkety	Does not exist
	zesty	Does not exist
linux-mako Launchpad, Ubuntu, Debian	artful	Does not exist
	precise	Does not exist
	trusty	Does not exist (trusty was ignored)
	upstream	Released (4.11~rc8)
	xenial	Ignored (abandoned)
	yakkety	Ignored (abandoned)
	zesty	Does not exist
linux-manta Launchpad, Ubuntu, Debian	artful	Does not exist
	precise	Does not exist
	trusty	Does not exist (trusty was ignored)
	upstream	Released (4.11~rc8)
	xenial	Does not exist
	yakkety	Does not exist
	zesty	Does not exist
linux-oem Launchpad, Ubuntu, Debian	artful	Does not exist
	precise	Does not exist
	trusty	Does not exist
	upstream	Released (4.11~rc8)
	xenial	Not vulnerable (4.13.0-1008.9)
	zesty	Does not exist
linux-qcm-msm Launchpad, Ubuntu, Debian	artful	Does not exist
	precise	Does not exist (precise was ignored [abandoned])
	trusty	Does not exist
	upstream	Released (4.11~rc8)
	xenial	Does not exist
	yakkety	Does not exist
	zesty	Does not exist
linux-raspi2 Launchpad, Ubuntu, Debian	artful	Not vulnerable (4.10.0-1006.8)
	precise	Does not exist
	trusty	Does not exist
	upstream	Released (4.11~rc8)
	xenial	Released (4.4.0-1057.64)
	yakkety	Ignored (reached end-of-life)
	zesty	Released (4.10.0-1006.8)
linux-snapdragon Launchpad, Ubuntu, Debian	artful	Not vulnerable (4.4.0-1059.63)
	precise	Does not exist
	trusty	Does not exist
	upstream	Released (4.11~rc8)
	xenial	Released (4.4.0-1059.63)
	yakkety	Released (4.4.0-1059.63)
	zesty	Released (4.4.0-1059.63)
linux-ti-omap4 Launchpad, Ubuntu, Debian	artful	Does not exist
	precise	Does not exist (precise was needed)
	trusty	Does not exist
	upstream	Released (4.11~rc8)
	xenial	Does not exist
	yakkety	Does not exist
	zesty	Does not exist

Severity score breakdown

Parameter	Value
Base score	4.4
Attack vector	Local
Attack complexity	Low
Privileges required	High
User interaction	None
Scope	Unchanged
Confidentiality	None
Integrity impact	High
Availability impact	None
Vector	CVSS:3.0/AV:L/AC:L/PR:H/UI:N/S:U/C:N/I:H/A:N

References

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