Bug 2024631 (CVE-2021-3995)
| Summary: | CVE-2021-3995 util-linux: Unauthorized unmount of FUSE filesystems belonging to users with similar uid | ||
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| Product: | [Other] Security Response | Reporter: | Pedro Sampaio <psampaio> |
| Component: | vulnerability | Assignee: | Red Hat Product Security <security-response-team> |
| Status: | CLOSED WONTFIX | QA Contact: | |
| Severity: | medium | Docs Contact: | |
| Priority: | medium | ||
| Version: | unspecified | CC: | bdettelb, caswilli, dhalasz, fjansen, jburrell, jonathan, jwong, kaycoth, kzak, micjohns, psegedy, rschiron, security-response-team, sthirugn, tkasparek, tsasak, vkrizan, vkumar, vmugicag |
| Target Milestone: | --- | Keywords: | Security |
| Target Release: | --- | ||
| Hardware: | All | ||
| OS: | Linux | ||
| Whiteboard: | |||
| Fixed In Version: | util-linux 2.37.3 | Doc Type: | If docs needed, set a value |
| Doc Text: |
A logic error was found in the libmount library of util-linux in the function that allows an unprivileged user to unmount a FUSE filesystem. This flaw allows an unprivileged local attacker to unmount FUSE filesystems that belong to certain other users who have a UID that is a prefix of the UID of the attacker in its string form. An attacker may use this flaw to cause a denial of service to applications that use the affected filesystems.
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Story Points: | --- |
| Clone Of: | Environment: | ||
| Last Closed: | 2022-05-17 15:45:11 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: | 2032274, 2044306 | ||
| Bug Blocks: | 2024641 | ||
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Description
Pedro Sampaio
2021-11-18 14:27:06 UTC
RHEL 6, 7 and 8 are not affected by this bug as they ship an older version of util-linux which does not allow unprivileged users to unmount FUSE mount points for the current user (e.g. is_fuse_usermount() function does not exist). Upstream patch: https://github.com/util-linux/util-linux/commit/57202f5713afa2af20ffbb6ab5331481d0396f8d Release notes: https://mirrors.edge.kernel.org/pub/linux/utils/util-linux/v2.37/v2.37.3-ReleaseNotes Created util-linux tracking bugs for this issue: Affects: fedora-all [bug 2044306] 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-2021-3995 |