Public Date:
1653855: CVE-2018-16864 systemd: stack overflow when calling syslog from a command with long cmdline
An allocation of memory without limits, that could result in the stack clashing with another memory region, was discovered in systemd-journald when a program with long command line arguments calls syslog. A local attacker may use this flaw to crash systemd-journald or escalate privileges.

Find out more about CVE-2018-16864 from the MITRE CVE dictionary dictionary and NIST NVD.


This issue affects the versions of systemd as shipped with Red Hat Enterprise Linux 7. Red Hat Product Security has rated this issue as having a security impact of Important because it allows a local attacker to crash systemd-journald or escalate his privileges. For additional information, refer to the Issue Severity Classification:

CVSS v3 metrics

CVSS3 Base Score 7.4
CVSS3 Base Metrics CVSS:3.0/AV:L/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H
Attack Vector Local
Attack Complexity High
Privileges Required None
User Interaction None
Scope Unchanged
Confidentiality High
Integrity Impact High
Availability Impact High

Red Hat Security Errata

Platform Errata Release Date
Red Hat Enterprise Linux 7 (systemd) RHSA-2019:0049 2019-01-14
Red Hat Virtualization 4 Management Agent for RHEL 7 Hosts (rhvm-appliance) RHSA-2019:0361 2019-02-18
Red Hat Enterprise Linux Extended Update Support 7.4 (systemd) RHSA-2019:0271 2019-02-04
Red Hat Enterprise Linux Update Services for SAP Solutions 7.3 (systemd) RHSA-2019:2402 2019-08-07
Red Hat Virtualization 4 Management Agent for RHEL 7 Hosts (redhat-virtualization-host) RHSA-2019:0342 2019-02-13
Red Hat Enterprise Linux Extended Update Support 7.5 (systemd) RHSA-2019:0204 2019-01-29
Red Hat Enterprise Linux Advanced Update Support 7.3 (systemd) RHSA-2019:2402 2019-08-07
Red Hat Enterprise Linux 7.3 Telco Extended Update Support (systemd) RHSA-2019:2402 2019-08-07

Affected Packages State

Platform Package State
Red Hat Enterprise Linux 8 systemd Not affected
Unless explicitly stated as not affected, all previous versions of packages in any minor update stream of a product listed here should be assumed vulnerable, although may not have been subject to full analysis.


Red Hat would like to thank Qualys Research Labs for reporting this issue.


To increase the time an attacker needs to exploit this flaw you could override the `StartLimitInterval=` (called StartLimitIntervalSec in newer systemd versions) and `StartLimitBurst=` settings. In this way the attack may require much longer to be successful.

To edit the journald service use `sudo systemctl edit systemd-journald.service` and add:


External References

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