Bug 1684607 (CVE-2019-3843)
| Summary: | CVE-2019-3843 systemd: services with DynamicUser can create SUID/SGID binaries | ||
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| Product: | [Other] Security Response | Reporter: | Riccardo Schirone <rschiron> |
| Component: | vulnerability | Assignee: | Red Hat Product Security <security-response-team> |
| Status: | CLOSED ERRATA | QA Contact: | |
| Severity: | medium | Docs Contact: | |
| Priority: | medium | ||
| Version: | unspecified | CC: | abhgupta, dbaker, jokerman, lnykryn, lpoetter, msekleta, security-response-team, s, sthangav, systemd-maint-list, systemd-maint, trankin, zbyszek, zjedrzej |
| Target Milestone: | --- | Keywords: | Security |
| Target Release: | --- | ||
| Hardware: | All | ||
| OS: | Linux | ||
| Whiteboard: | |||
| Fixed In Version: | systemd 242 | Doc Type: | If docs needed, set a value |
| Doc Text: |
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.
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Story Points: | --- |
| Clone Of: | Environment: | ||
| Last Closed: | 2020-04-28 16:32:35 UTC | Type: | --- |
| Regression: | --- | Mount Type: | --- |
| Documentation: | --- | CRM: | |
| Verified Versions: | Category: | --- | |
| oVirt Team: | --- | RHEL 7.3 requirements from Atomic Host: | |
| Cloudforms Team: | --- | Target Upstream Version: | |
| Embargoed: | |||
| Bug Depends On: | 1687512, 1703356 | ||
| Bug Blocks: | 1672544 | ||
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Description
Riccardo Schirone
2019-03-01 16:04:35 UTC
A compromised or malicious service that uses DynamicUser property could leave on the filesystem a SUID/SGID binary that would allow other users to execute programs with the privileges of the transient user/group created by systemd. If the same UID/GID is reused by another service in the future, the SUID/SGID binary can be used to access the new service's resources. 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. Upstream patches: https://github.com/systemd/systemd/commit/3c27973b13724ede05a06a5d346a569794cda433 https://github.com/systemd/systemd/commit/f69567cbe26d09eac9d387c0be0fc32c65a83ada https://github.com/systemd/systemd/commit/9d880b70ba5c6ca83c82952f4c90e86e56c7b70c https://github.com/systemd/systemd/commit/7445db6eb70e8d5989f481d0c5a08ace7047ae5b https://github.com/systemd/systemd/commit/62aa29247c3d74bcec0607c347f2be23cd90675d https://github.com/systemd/systemd/commit/bf65b7e0c9fc215897b676ab9a7c9d1c688143ba References: https://bugs.chromium.org/p/project-zero/issues/detail?id=1771 https://bugs.launchpad.net/ubuntu/+source/systemd/+bug/1814596 Created systemd tracking bugs for this issue: Affects: fedora-all [bug 1703356] https://github.com/systemd/systemd-stable/pull/54 contains a backport for v241-stable. Acknowledgments: Name: Jann Horn (Google Project Zero) This issue has been addressed in the following products: Red Hat Enterprise Linux 8 Via RHSA-2020:1794 https://access.redhat.com/errata/RHSA-2020:1794 This bug is now closed. Further updates for individual products will be reflected on the CVE page(s): https://access.redhat.com/security/cve/cve-2019-3843 |