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 his privileges. Versions through v240 are vulnerable.

An out of bounds read was discovered in systemd-journald in the way it parses log messages that terminate with a colon ':'. A local attacker can use this flaw to disclose process memory data. Versions from v221 to v239 are vulnerable.

A buffer overflow vulnerability in the dhcp6 client of systemd allows a malicious dhcp6 server to overwrite heap memory in systemd-networkd. Affected releases are systemd: versions up to and including 239.

A race condition in chown_one() of systemd allows an attacker to cause systemd to set arbitrary permissions on arbitrary files. Affected releases are systemd versions up to and including 239.

A vulnerability in unit_deserialize of systemd allows an attacker to supply arbitrary state across systemd re-execution via NotifyAccess. This can be used to improperly influence systemd execution and possibly lead to root privilege escalation. Affected releases are systemd versions up to and including 239.

An issue was discovered in UCMS 1.4.6 and 1.6. It allows PHP code injection during installation via the systemdomain parameter to install/index.php, as demonstrated by injecting a phpinfo() call into /inc/config.php.

Spring Boot supports an embedded launch script that can be used to easily run the application as a systemd or init.d linux service. The script included with Spring Boot 1.5.9 and earlier and 2.0.0.M1 through 2.0.0.M7 is susceptible to a symlink attack which allows the "run_user" to overwrite and take ownership of any file on the same system. In order to instigate the attack, the application must be installed as a service and the "run_user" requires shell access to the server. Spring Boot application that are not installed as a service, or are not using the embedded launch script are not susceptible.

In systemd prior to 234 a race condition exists between .mount and .automount units such that automount requests from kernel may not be serviced by systemd resulting in kernel holding the mountpoint and any processes that try to use said mount will hang. A race condition like this may lead to denial of service, until mount points are unmounted.

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.

In snapd 2.27 through 2.29.2 the 'snap logs' command could be made to call journalctl without match arguments and therefore allow unprivileged, unauthenticated users to bypass systemd-journald's access restrictions.

systemd-tmpfiles in systemd before 237 attempts to support ownership/permission changes on hardlinked files even if the fs.protected_hardlinks sysctl is turned off, which allows local users to bypass intended access restrictions via vectors involving a hard link to a file for which the user lacks write access, as demonstrated by changing the ownership of the /etc/passwd file.

In systemd 223 through 235, a remote DNS server can respond with a custom crafted DNS NSEC resource record to trigger an infinite loop in the dns_packet_read_type_window() function of the 'systemd-resolved' service and cause a DoS of the affected service.

Stack-based buffer overflow in the getpwnam and getgrnam functions of the NSS module nss-mymachines in systemd.

debian/tor.init in the Debian tor_0.2.9.11-1~deb9u1 package for Tor was designed to execute aa-exec from the standard system pathname if the apparmor package is installed, but implements this incorrectly (with a wrong assumption that the specific pathname would remain the same forever), which allows attackers to bypass intended AppArmor restrictions by leveraging the silent loss of this protection mechanism. NOTE: this does not affect systems, such as default Debian stretch installations, on which Tor startup relies on a systemd unit file (instead of this tor.init script).

systemd v233 and earlier fails to safely parse usernames starting with a numeric digit (e.g. "0day"), running the service in question with root privileges rather than the user intended.

In systemd through 233, certain sizes passed to dns_packet_new in systemd-resolved can cause it to allocate a buffer that's too small. A malicious DNS server can exploit this via a response with a specially crafted TCP payload to trick systemd-resolved into allocating a buffer that's too small, and subsequently write arbitrary data beyond the end of it.

systemd-resolved through 233 allows remote attackers to cause a denial of service (daemon crash) via a crafted DNS response with an empty question section.

LightDM through 1.22.0, when systemd is used in Ubuntu 16.10 and 17.x, allows physically proximate attackers to bypass intended AppArmor restrictions and visit the home directories of arbitrary users by establishing a guest session.

An issue was discovered in AppArmor before 2.12. Incorrect handling of unknown AppArmor profiles in AppArmor init scripts, upstart jobs, and/or systemd unit files allows an attacker to possibly have increased attack surfaces of processes that were intended to be confined by AppArmor. This is due to the common logic to handle 'restart' operations removing AppArmor profiles that aren't found in the typical filesystem locations, such as /etc/apparmor.d/. Userspace projects that manage their own AppArmor profiles in atypical directories, such as what's done by LXD and Docker, are affected by this flaw in the AppArmor init script logic.

A flaw in systemd v228 in /src/basic/fs-util.c caused world writable suid files to be created when using the systemd timers features, allowing local attackers to escalate their privileges to root. This is fixed in v229.