CVE-2018-16888

It was discovered systemd does not correctly check the content of PIDFile files before using it to kill processes. When a service is run from an unprivileged user (e.g. User field set in the service file), a local attacker who is able to write to the PIDFile of the mentioned service may use this flaw to trick systemd into killing other services and/or privileged processes. Versions before v237 are vulnerable.

Published: 2019-01-14 Last update: 2024-11-21 Assigner: [email protected] Source: [email protected]

Conclusion & alert: CVE-2018-16888 is rated Low Risk (32.2/100): CVSS Medium severity, with low exploitation likelihood (EPSS 0.17%). Mandatory action: Monitor for updates and reassess as exploit intelligence or EPSS changes.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2018-16888

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2025-11-21 0.07% 0.17% +0.10%
2 2025-11-18 0.18% 0.07% -0.11%
3 2025-09-02 0.18%

Full EPSS history (7 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2018-16888

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
4.7 3.1 MEDIUM
CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H Click to expand
Attack vector (AV:L)
They already need access on the box, or another person has to do something wrong; it’s not a remote drive-by.
Attack complexity (AC:H)
Even with access, the exploit needs extra luck, timing, or a fussy environment to actually work.
Privileges required (PR:L)
A normal user session is enough; they don’t have to be admin.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:N)
Doesn’t really leak secrets in a meaningful way.
Integrity (I:N)
Data isn’t meaningfully altered or forged.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
1.0 3.6 [email protected]
4.4 3.0 MEDIUM
CVSS:3.0/AV:L/AC:H/PR:L/UI:R/S:U/C:N/I:N/A:H Click to expand
Attack vector (AV:L)
They already need access on the box, or another person has to do something wrong; it’s not a remote drive-by.
Attack complexity (AC:H)
Even with access, the exploit needs extra luck, timing, or a fussy environment to actually work.
Privileges required (PR:L)
A normal user session is enough; they don’t have to be admin.
User interaction (UI:R)
A real person has to do something—click, install, enable—otherwise it doesn’t land.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:N)
Doesn’t really leak secrets in a meaningful way.
Integrity (I:N)
Data isn’t meaningfully altered or forged.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
0.8 3.6 [email protected]
1.9 2.0 LOW
AV:L/AC:M/Au:N/C:N/I:N/A:P Click to expand
Access vector (AV:L)
Requires local access to the target system.
Access complexity (AC:M)
Exploitation needs some favorable conditions, but not exceptional ones.
Authentication (AU:N)
No authentication is required.
Confidentiality impact (C:N)
No confidentiality impact.
Integrity impact (I:N)
No integrity impact.
Availability impact (A:P)
Partial availability impact.
3.4 2.9 [email protected]

Weakness enumeration for CVE-2018-16888

OS Trackers for CVE-2018-16888

vendor priority summary link
debian low CVE-2018-16888 low priority: Debian including 1 source packages (systemd), 5 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): resolved 5. https://security-tracker.debian.org/tracker/CVE-2018-16888
redhat low https://access.redhat.com/security/cve/CVE-2018-16888
suse medium CVE-2018-16888 severity moderate: SUSE including 10 source package names (libgudev1-219-67.el7, libgudev1-devel-219-67.el7, …), 10 product×package rows across 1 product lines (SUSE Liberty Linux 7): Fixed 10. https://www.suse.com/security/cve/CVE-2018-16888/
ubuntu low CVE-2018-16888 low priority: Ubuntu including 1 source packages (systemd), 7 status rows across 7 suites (bionic, cosmic, disco, eoan, trusty, upstream, xenial): not-affected 5, released 2. https://ubuntu.com/security/CVE-2018-16888

Affected software / configurations for CVE-2018-16888

Vendor Product Version Raw CPE
systemd_project systemd < 237 cpe:2.3:a:systemd_project:systemd:*:*:*:*:*:*:*:*
canonical ubuntu_linux 16.04 cpe:2.3:o:canonical:ubuntu_linux:16.04:*:*:*:esm:*:*:*
canonical ubuntu_linux 18.04 cpe:2.3:o:canonical:ubuntu_linux:18.04:*:*:*:lts:*:*:*
canonical ubuntu_linux 19.10 cpe:2.3:o:canonical:ubuntu_linux:19.10:*:*:*:*:*:*:*
redhat enterprise_linux 7.0 cpe:2.3:o:redhat:enterprise_linux:7.0:*:*:*:*:*:*:*
netapp active_iq_performance_analytics_services cpe:2.3:a:netapp:active_iq_performance_analytics_services:-:*:*:*:*:*:*:*
netapp element_software cpe:2.3:a:netapp:element_software:-:*:*:*:*:*:*:*

References for CVE-2018-16888

cvelogic Threat Intelligence