CVE-2018-6954

2018-02-1300:00:00

ubuntu.com

7.8 High

CVSS3

Attack Vector

LOCAL

Attack Complexity

LOW

Privileges Required

LOW

User Interaction

NONE

Scope

UNCHANGED

Confidentiality Impact

HIGH

Integrity Impact

HIGH

Availability Impact

HIGH

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

7.2 High

CVSS2

Access Vector

LOCAL

Access Complexity

LOW

Authentication

NONE

Confidentiality Impact

COMPLETE

Integrity Impact

COMPLETE

Availability Impact

COMPLETE

AV:L/AC:L/Au:N/C:C/I:C/A:C

0.0004 Low

EPSS

Percentile

5.3%

JSON

systemd-tmpfiles in systemd through 237 mishandles symlinks present in
non-terminal path components, which allows local users to obtain ownership
of arbitrary files via vectors involving creation of a directory and a file
under that directory, and later replacing that directory with a symlink.
This occurs even if the fs.protected_symlinks sysctl is turned on.

Bugs

Notes

Author	Note
mdeslaur	original fix was incomplete, see second pull
chrisccoulson	Fix reverted in xenial because it breaks containers running on pre-2.6.39 kernels
mdeslaur	fix was re-introduced in xenial in 229-4ubuntu21.15

OSVersionArchitecturePackageVersionFilename
ubuntu18.04noarchsystemd< 237-3ubuntu10.9UNKNOWN
ubuntu18.10noarchsystemd< 239-7ubuntu10.4UNKNOWN
ubuntu16.04noarchsystemd< 229-4ubuntu21.15UNKNOWN