It was discovered that a systemd service that uses DynamicUser property can create a SUID/SGID binary that would be allowed to run as the transient service UID/GID even after the service is terminated. A local attacker may use this flaw to access resources that will be owned by a potentially different service in the future, when the UID/GID will be recycled.

The remote Oracle Linux 8 host has packages installed that are affected by multiple vulnerabilities as referenced in the ELSA-2020-1794 advisory.

    - sd-bus: use 'queue' message references for managing r/w message queues in connection objects     (CVE-2020-1712)
    - sd-bus: make rqueue/wqueue sizes of type size_t (CVE-2020-1712)
    - sd-bus: reorder bus ref and bus message ref handling (CVE-2020-1712)
    - sd-bus: make sure dispatch_rqueue() initializes return parameter on all types of success (CVE-2020-1712)
    - sd-bus: drop two inappropriate empty lines (CVE-2020-1712)
    - sd-bus: initialize mutex after we allocated the wqueue (CVE-2020-1712)
    - sd-bus: always go through sd_bus_unref() to free messages (CVE-2020-1712)
    - bus-message: introduce two kinds of references to bus messages (CVE-2020-1712)
    - sd-bus: introduce API for re-enqueuing incoming messages (CVE-2020-1712)
    - sd-event: add sd_event_source_disable_unref() helper (CVE-2020-1712)
    - polkit: when authorizing via PK lets re-resolve callback/userdata instead of caching it (CVE-2020-1712)

Tenable has extracted the preceding description block directly from the Oracle Linux security advisory.

Note that Nessus has not tested for these issues but has instead relied only on the application's self-reported version number.

The remote CentOS Linux 8 host has packages installed that are affected by multiple vulnerabilities as referenced in the CESA-2020:1794 advisory.

  - systemd: services with DynamicUser can create SUID/SGID binaries (CVE-2019-3843)

  - systemd: services with DynamicUser can get new privileges and create SGID binaries (CVE-2019-3844)

Note that Nessus has not tested for this issue but has instead relied only on the application's self-reported version number.

The remote Redhat Enterprise Linux 8 host has packages installed that are affected by multiple vulnerabilities as referenced in the RHSA-2020:1794 advisory.

    The systemd packages contain systemd, a system and service manager for Linux, compatible with the SysV and     LSB init scripts. It provides aggressive parallelism capabilities, uses socket and D-Bus activation for     starting services, offers on-demand starting of daemons, and keeps track of processes using Linux cgroups.
    In addition, it supports snapshotting and restoring of the system state, maintains mount and automount     points, and implements an elaborate transactional dependency-based service control logic. It can also work     as a drop-in replacement for sysvinit.

    Security Fix(es):

    * systemd: services with DynamicUser can create SUID/SGID binaries (CVE-2019-3843)

    * systemd: services with DynamicUser can get new privileges and create SGID binaries (CVE-2019-3844)

    For more details about the security issue(s), including the impact, a CVSS score, acknowledgments, and     other related information, refer to the CVE page(s) listed in the References section.

    Additional Changes:

    For detailed information on changes in this release, see the Red Hat Enterprise Linux 8.2 Release Notes     linked from the References section.

Tenable has extracted the preceding description block directly from the Red Hat Enterprise Linux security advisory.

Note that Nessus has not tested for these issues but has instead relied only on the application's self-reported version number.

The remote Ubuntu 16.04 LTS / 18.04 LTS host has packages installed that are affected by multiple vulnerabilities as referenced in the USN-4269-1 advisory.

    It was discovered that systemd incorrectly handled certain PIDFile files. A local attacker could possibly     use this issue to trick systemd into killing privileged processes. This issue only affected Ubuntu 16.04     LTS. (CVE-2018-16888)

    It was discovered that systemd incorrectly handled certain udevadm trigger commands. A local attacker     could possibly use this issue to cause systemd to consume resources, leading to a denial of service.
    (CVE-2019-20386)

    Jann Horn discovered that systemd incorrectly handled services that use the DynamicUser property. A local     attacker could possibly use this issue to access resources owned by a different service in the future.
    This issue only affected Ubuntu 18.04 LTS. (CVE-2019-3843, CVE-2019-3844)

    Tavis Ormandy discovered that systemd incorrectly handled certain Polkit queries. A local attacker could     use this issue to cause systemd to crash, resulting in a denial of service, or possibly execute arbitrary     code and escalate privileges. (CVE-2020-1712)

Tenable has extracted the preceding description block directly from the Ubuntu security advisory.

Note that Nessus has not tested for these issues but has instead relied only on the application's self-reported version number.

According to the versions of the systemd packages installed, the EulerOS Virtualization for ARM 64 installation on the remote host is affected by the following vulnerabilities :

  - It was discovered that a systemd service that uses     DynamicUser property can create a SUID/SGID binary that     would be allowed to run as the transient service     UID/GID even after the service is terminated. A local     attacker may use this flaw to access resources that     will be owned by a potentially different service in the     future, when the UID/GID will be     recycled.(CVE-2019-3843)

  - It was discovered that a systemd service that uses     DynamicUser property can get new privileges through the     execution of SUID binaries, which would allow to create     binaries owned by the service transient group with the     setgid bit set. A local attacker may use this flaw to     access resources that will be owned by a potentially     different service in the future, when the GID will be     recycled.(CVE-2019-3844)

Note that Tenable Network Security has extracted the preceding description block directly from the EulerOS security advisory. Tenable has attempted to automatically clean and format it as much as possible without introducing additional issues.

An update of the systemd package has been released.

This update for systemd fixes the following issues :

Security issues fixed :

CVE-2019-3842: Fixed a privilege escalation in pam_systemd which could be exploited by a local user (bsc#1132348).

CVE-2019-6454: Fixed a denial of service via crafted D-Bus message (bsc#1125352).

CVE-2019-3843, CVE-2019-3844: Fixed a privilege escalation where services with DynamicUser could gain new privileges or create SUID/SGID binaries (bsc#1133506, bsc#1133509).

Non-security issued fixed: logind: fix killing of scopes (bsc#1125604)

namespace: make MountFlags=shared work again (bsc#1124122)

rules: load drivers only on 'add' events (bsc#1126056)

sysctl: Don't pass null directive argument to '%s' (bsc#1121563)

systemd-coredump: generate a stack trace of all core dumps and log into the journal (jsc#SLE-5933)

udevd: notify when max number value of children is reached only once per batch of events (bsc#1132400)

sd-bus: bump message queue size again (bsc#1132721)

Do not automatically online memory on s390x (bsc#1127557)

Removed sg.conf (bsc#1036463)

Note that Tenable Network Security has extracted the preceding description block directly from the SUSE security advisory. Tenable has attempted to automatically clean and format it as much as possible without introducing additional issues.

According to the versions of the systemd packages installed, the EulerOS installation on the remote host is affected by the following vulnerabilities :

  - It was discovered that a systemd service that uses     DynamicUser property can get new privileges through the     execution of SUID binaries, which would allow a     cooperating process to create binaries owned by the     service transient group with the setgid bit set. A     local attacker may use this flaw to access resources     that will be owned by a potentially different service     in the future when the GID will be     recycled.(CVE-2019-3844)

  - It was discovered that a systemd service that uses     DynamicUser property can create a SUID/SGID binary that     would be allowed to run as the transient service     UID/GID even after the service is terminated. A local     attacker may use this flaw to access resources that     will be owned by a potentially different service in the     future when the UID/GID will be     recycled.(CVE-2019-3843)

  - In systemd before v242-rc4, it was discovered that     pam_systemd does not properly sanitize the environment     before using the XDG_SEAT variable. It is possible for     an attacker, in some particular configurations, to set     a XDG_SEAT environment variable which allows for     commands to be checked against polkit policies using     the 'allow_active' element rather than     'allow_any'.(CVE-2019-3842)

Note that Tenable Network Security has extracted the preceding description block directly from the EulerOS security advisory. Tenable has attempted to automatically clean and format it as much as possible without introducing additional issues.

- Fix hang in flush_accept (#1702358)

  - Fix handling of RUN keys in udevd

  - Some documentation and minor logging fixes

  - Backport the addition of RestrictSUIDSGID= from     systemd-242 and enable RestrictSUIDSGID=yes for systemd     services which use DynamicUser=yes (#1703356,     CVE-2019-3843). The defaults in v242 were changed to     enable RestrictSUIDSGID=yes if DynamicUser=yes is     specified, but this backport doesn't do this and     RestrictSUIDSGID=yes has to be requested explicitly.
    Maintainers of other services packages for Fedora should     consider doing this.

No need to log out or reboot.

Note that Tenable Network Security has extracted the preceding description block directly from the Fedora update system website.
Tenable has attempted to automatically clean and format it as much as possible without introducing additional issues.

ID	Name	Product	Family	Severity
180927	Oracle Linux 8 : systemd (ELSA-2020-1794)	Nessus	Oracle Linux Local Security Checks	high
145995	CentOS 8 : systemd (CESA-2020:1794)	Nessus	CentOS Local Security Checks	high
136046	RHEL 8 : systemd (RHSA-2020:1794)	Nessus	Red Hat Local Security Checks	high
133523	Ubuntu 16.04 LTS / 18.04 LTS : systemd vulnerabilities (USN-4269-1)	Nessus	Ubuntu Local Security Checks	high
131484	EulerOS Virtualization for ARM 64 3.0.3.0 : systemd (EulerOS-SA-2019-2319)	Nessus	Huawei Local Security Checks	high
128160	Photon OS 3.0: Systemd PHSA-2019-3.0-0024	Nessus	PhotonOS Local Security Checks	high
126736	SUSE SLED15 / SLES15 Security Update : systemd (SUSE-SU-2019:1364-2)	Nessus	SuSE Local Security Checks	high
126288	EulerOS 2.0 SP8 : systemd (EulerOS-SA-2019-1661)	Nessus	Huawei Local Security Checks	high
125537	SUSE SLED15 / SLES15 Security Update : systemd (SUSE-SU-2019:1364-1)	Nessus	SuSE Local Security Checks	high
124504	Fedora 30 : systemd (2019-7322053e74)	Nessus	Fedora Local Security Checks	high

Detections

Analytics

CVE-2019-3843

high

Tenable Plugins

high

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