CVE-2018-18955
Published: 16 November 2018
In the Linux kernel 4.15.x through 4.19.x before 4.19.2, map_write() in kernel/user_namespace.c allows privilege escalation because it mishandles nested user namespaces with more than 5 UID or GID ranges. A user who has CAP_SYS_ADMIN in an affected user namespace can bypass access controls on resources outside the namespace, as demonstrated by reading /etc/shadow. This occurs because an ID transformation takes place properly for the namespaced-to-kernel direction but not for the kernel-to-namespaced direction.
From the Ubuntu Security Team
Jann Horn discovered that the Linux kernel mishandles mapping UID or GID ranges inside nested user namespaces in some situations. A local attacker could use this to bypass access controls on resources outside the namespace.
Priority
Status
Package | Release | Status |
---|---|---|
linux
Launchpad, Ubuntu, Debian |
bionic |
Released
(4.15.0-42.45)
|
cosmic |
Released
(4.18.0-12.13)
|
|
trusty |
Not vulnerable
(3.11.0-12.19)
|
|
upstream |
Released
(4.20~rc2)
|
|
xenial |
Not vulnerable
(4.2.0-16.19)
|
|
Patches:
Introduced by
6397fac4915ab3002dc15aae751455da1a852f25
|
||
linux-aws
Launchpad, Ubuntu, Debian |
bionic |
Released
(4.15.0-1029.30)
|
cosmic |
Released
(4.18.0-1006.7)
|
|
trusty |
Not vulnerable
(4.4.0-1002.2)
|
|
upstream |
Released
(4.20~rc2)
|
|
xenial |
Not vulnerable
(4.4.0-1001.10)
|
|
linux-aws-hwe
Launchpad, Ubuntu, Debian |
bionic |
Does not exist
|
cosmic |
Does not exist
|
|
trusty |
Does not exist
|
|
upstream |
Released
(4.20~rc2)
|
|
xenial |
Not vulnerable
(4.15.0-1030.31~16.04.1)
|
|
linux-azure
Launchpad, Ubuntu, Debian |
bionic |
Released
(4.15.0-1035.36)
|
cosmic |
Released
(4.18.0-1006.6)
|
|
trusty |
Released
(4.15.0-1035.36~14.04.2)
|
|
upstream |
Released
(4.20~rc2)
|
|
xenial |
Released
(4.15.0-1035.36~16.04.1)
|
|
linux-azure-edge
Launchpad, Ubuntu, Debian |
bionic |
Released
(4.15.0-1035.36)
|
cosmic |
Does not exist
|
|
trusty |
Does not exist
|
|
upstream |
Released
(4.20~rc2)
|
|
xenial |
Released
(4.15.0-1035.36~16.04.1)
|
|
linux-euclid
Launchpad, Ubuntu, Debian |
bionic |
Does not exist
|
cosmic |
Does not exist
|
|
trusty |
Does not exist
|
|
upstream |
Released
(4.20~rc2)
|
|
xenial |
Not vulnerable
(4.4.0-9019.20)
|
|
linux-flo
Launchpad, Ubuntu, Debian |
bionic |
Does not exist
|
cosmic |
Does not exist
|
|
trusty |
Does not exist
(trusty was ignored [abandoned])
|
|
upstream |
Released
(4.20~rc2)
|
|
xenial |
Ignored
(abandoned)
|
|
linux-gcp
Launchpad, Ubuntu, Debian |
bionic |
Released
(4.15.0-1025.26)
|
cosmic |
Released
(4.18.0-1004.5)
|
|
trusty |
Does not exist
|
|
upstream |
Released
(4.20~rc2)
|
|
xenial |
Released
(4.15.0-1025.26~16.04.1)
|
|
linux-gcp-edge
Launchpad, Ubuntu, Debian |
bionic |
Not vulnerable
(4.18.0-1004.5~18.04.1)
|
cosmic |
Does not exist
|
|
trusty |
Does not exist
|
|
upstream |
Released
(4.20~rc2)
|
|
xenial |
Does not exist
|
|
linux-gke
Launchpad, Ubuntu, Debian |
bionic |
Does not exist
|
cosmic |
Does not exist
|
|
trusty |
Does not exist
|
|
upstream |
Released
(4.20~rc2)
|
|
xenial |
Ignored
(end of standard support)
|
|
linux-goldfish
Launchpad, Ubuntu, Debian |
bionic |
Does not exist
|
cosmic |
Does not exist
|
|
trusty |
Does not exist
(trusty was ignored [abandoned])
|
|
upstream |
Released
(4.20~rc2)
|
|
xenial |
Ignored
(end of life)
|
|
linux-grouper
Launchpad, Ubuntu, Debian |
bionic |
Does not exist
|
cosmic |
Does not exist
|
|
trusty |
Does not exist
(trusty was ignored [abandoned])
|
|
upstream |
Released
(4.20~rc2)
|
|
xenial |
Does not exist
|
|
linux-hwe
Launchpad, Ubuntu, Debian |
bionic |
Not vulnerable
(4.18.0-13.14~18.04.1)
|
cosmic |
Does not exist
|
|
trusty |
Does not exist
|
|
upstream |
Released
(4.20~rc2)
|
|
xenial |
Released
(4.15.0-42.45~16.04.1)
|
|
linux-hwe-edge
Launchpad, Ubuntu, Debian |
bionic |
Not vulnerable
(4.18.0-12.13~18.04.1)
|
cosmic |
Does not exist
|
|
trusty |
Does not exist
|
|
upstream |
Released
(4.20~rc2)
|
|
xenial |
Released
(4.15.0-42.45~16.04.1)
|
|
linux-kvm
Launchpad, Ubuntu, Debian |
bionic |
Released
(4.15.0-1027.27)
|
cosmic |
Released
(4.18.0-1005.5)
|
|
trusty |
Does not exist
|
|
upstream |
Released
(4.20~rc2)
|
|
xenial |
Not vulnerable
(4.4.0-1004.9)
|
|
linux-lts-trusty
Launchpad, Ubuntu, Debian |
bionic |
Does not exist
|
cosmic |
Does not exist
|
|
trusty |
Does not exist
|
|
upstream |
Released
(4.20~rc2)
|
|
xenial |
Does not exist
|
|
linux-lts-utopic
Launchpad, Ubuntu, Debian |
bionic |
Does not exist
|
cosmic |
Does not exist
|
|
trusty |
Does not exist
(trusty was ignored [end of standard support])
|
|
upstream |
Released
(4.20~rc2)
|
|
xenial |
Does not exist
|
|
linux-lts-vivid
Launchpad, Ubuntu, Debian |
bionic |
Does not exist
|
cosmic |
Does not exist
|
|
trusty |
Does not exist
(trusty was ignored [end of standard support])
|
|
upstream |
Released
(4.20~rc2)
|
|
xenial |
Does not exist
|
|
linux-lts-wily
Launchpad, Ubuntu, Debian |
bionic |
Does not exist
|
cosmic |
Does not exist
|
|
trusty |
Does not exist
(trusty was ignored [end of standard support])
|
|
upstream |
Released
(4.20~rc2)
|
|
xenial |
Does not exist
|
|
linux-lts-xenial
Launchpad, Ubuntu, Debian |
bionic |
Does not exist
|
cosmic |
Does not exist
|
|
trusty |
Not vulnerable
(4.4.0-13.29~14.04.1)
|
|
upstream |
Released
(4.20~rc2)
|
|
xenial |
Does not exist
|
|
linux-maguro
Launchpad, Ubuntu, Debian |
bionic |
Does not exist
|
cosmic |
Does not exist
|
|
trusty |
Does not exist
(trusty was ignored [abandoned])
|
|
upstream |
Released
(4.20~rc2)
|
|
xenial |
Does not exist
|
|
linux-mako
Launchpad, Ubuntu, Debian |
bionic |
Does not exist
|
cosmic |
Does not exist
|
|
trusty |
Does not exist
(trusty was ignored [abandoned])
|
|
upstream |
Released
(4.20~rc2)
|
|
xenial |
Ignored
(abandoned)
|
|
linux-manta
Launchpad, Ubuntu, Debian |
bionic |
Does not exist
|
cosmic |
Does not exist
|
|
trusty |
Does not exist
(trusty was ignored [abandoned])
|
|
upstream |
Released
(4.20~rc2)
|
|
xenial |
Does not exist
|
|
linux-oem
Launchpad, Ubuntu, Debian |
bionic |
Released
(4.15.0-1028.33)
|
cosmic |
Released
(4.15.0-1028.33)
|
|
trusty |
Does not exist
|
|
upstream |
Released
(4.20~rc2)
|
|
xenial |
Ignored
(end of standard support, was needs-triage)
|
|
linux-oracle
Launchpad, Ubuntu, Debian |
bionic |
Not vulnerable
(4.15.0-1007.9)
|
cosmic |
Not vulnerable
|
|
trusty |
Does not exist
|
|
upstream |
Released
(4.20~rc2)
|
|
xenial |
Not vulnerable
(4.15.0-1007.9~16.04.1)
|
|
linux-raspi2
Launchpad, Ubuntu, Debian |
bionic |
Released
(4.15.0-1029.31)
|
cosmic |
Released
(4.18.0-1007.9)
|
|
trusty |
Does not exist
|
|
upstream |
Released
(4.20~rc2)
|
|
xenial |
Not vulnerable
(4.2.0-1013.19)
|
|
linux-snapdragon
Launchpad, Ubuntu, Debian |
bionic |
Not vulnerable
|
cosmic |
Does not exist
|
|
trusty |
Does not exist
|
|
upstream |
Released
(4.20~rc2)
|
|
xenial |
Not vulnerable
(4.4.0-1012.12)
|
Severity score breakdown
Parameter | Value |
---|---|
Base score | 7.0 |
Attack vector | Local |
Attack complexity | High |
Privileges required | Low |
User interaction | None |
Scope | Unchanged |
Confidentiality | High |
Integrity impact | High |
Availability impact | High |
Vector | CVSS:3.0/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H |
References
- https://ubuntu.com/security/notices/USN-3832-1
- https://ubuntu.com/security/notices/USN-3833-1
- https://ubuntu.com/security/notices/USN-3836-1
- https://ubuntu.com/security/notices/USN-3835-1
- https://ubuntu.com/security/notices/USN-3836-2
- https://www.cve.org/CVERecord?id=CVE-2018-18955
- NVD
- Launchpad
- Debian