CVE-2018-6954
Published: 13 February 2018
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.
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 |
Priority
Status
Package | Release | Status |
---|---|---|
systemd Launchpad, Ubuntu, Debian |
artful |
Ignored
(end of life)
|
bionic |
Released
(237-3ubuntu10.9)
|
|
cosmic |
Released
(239-7ubuntu10.4)
|
|
trusty |
Not vulnerable
(binary not built)
|
|
upstream |
Needs triage
|
|
xenial |
Released
(229-4ubuntu21.15)
|
|
Patches: upstream: https://github.com/systemd/systemd/pull/8358 upstream: https://github.com/systemd/systemd/pull/8822 upstream: https://github.com/systemd/systemd/commit/936f6bdb803c432578e2cdcc5f93f3bfff93aff0 |
Severity score breakdown
Parameter | Value |
---|---|
Base score | 7.8 |
Attack vector | Local |
Attack complexity | Low |
Privileges required | Low |
User interaction | None |
Scope | Unchanged |
Confidentiality | High |
Integrity impact | High |
Availability impact | High |
Vector | CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H |