Headline
CVE-2019-3844: services with DynamicUser can get new privileges and create SGID binaries
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.
Description Riccardo Schirone 2019-03-01 16:08:31 UTC
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.
Comment 2 Riccardo Schirone 2019-03-05 13:33:22 UTC
Statement:
This issue did not affect the versions of systemd as shipped with Red Hat Enterprise Linux 7 as they did not include support for DynamicUser property.
Comment 19 Riccardo Schirone 2019-04-26 08:41:29 UTC
Created systemd tracking bugs for this issue:
Affects: fedora-all [bug 1703357]
Comment 20 Riccardo Schirone 2019-04-26 13:39:15 UTC
Acknowledgments:
Name: Jann Horn (Google Project Zero)
Comment 23 mathangi.shankar 2020-03-02 09:35:56 UTC
Hello,
I am encountering this bug, on SAS Viya server installed on Red Hat Linux 7.6. Can you please suggest what is the fix for this issue?
Thanks in advance, Mathangi