Bug 1964129 (CVE-2021-35939)
Summary: | CVE-2021-35939 rpm: checks for unsafe symlinks are not performed for intermediary directories | ||
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Product: | [Other] Security Response | Reporter: | msiddiqu |
Component: | vulnerability | Assignee: | Nobody <nobody> |
Status: | NEW --- | QA Contact: | |
Severity: | medium | Docs Contact: | |
Priority: | medium | ||
Version: | unspecified | CC: | caswilli, derrick.roach.ctr, ffesti, kaycoth, packaging-team-maint, pmatilai, sbueno, vmugicag, vmukhame |
Target Milestone: | --- | Keywords: | Security |
Target Release: | --- | ||
Hardware: | All | ||
OS: | Linux | ||
Whiteboard: | |||
Fixed In Version: | rpm 4.18.0 | Doc Type: | If docs needed, set a value |
Doc Text: |
It was found that the fix for CVE-2017-7500 and CVE-2017-7501 was incomplete: the check was only implemented for the parent directory of the file to be created. A local unprivileged user who owns another ancestor directory could potentially use this flaw to gain root privileges. The highest threat from this vulnerability is to data confidentiality and integrity as well as system availability.
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Story Points: | --- |
Clone Of: | Environment: | ||
Last Closed: | 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: | 1969334, 1969333, 1969335, 1969804, 1969805, 1969806, 1977848, 1978167, 1978169, 1978170, 1978171, 2003067, 2070455 | ||
Bug Blocks: | 1964123, 1977374 |
Description
msiddiqu
2021-05-24 19:00:44 UTC
Created rpm tracking bugs for this issue: Affects: fedora-all [bug 1977848] This flaw, along with CVE-2021-35937 and CVE-2021-35938, belong to a set of complex issues that may allow an unprivileged user to trick RPM into modifying root-owned files during installation, due to race conditions and/or symlink attacks. These issues do not have a solution upstream. Fixing would require rather involved refactoring of RPM internals. Note that in this context, unprivileged users are actually system accounts (like the pcpqa user mentioned in one of the SUSE bugs) that are usually more tightly controlled than ordinary users. In general, access to files and directories installed by RPMs requires high privileges. Regular users should not be allowed to manipulate RPM artifacts during installation. A local attacker would first need to compromise a system account in order to exploit these flaws, thus reducing the overall impact considerably. This is considered fixed in RPM 4.18 (https://rpm.org/wiki/Releases/4.18.0) which is currently in alpha stage of the release process, final version is expected in Q3. Upstream PR & commit: https://github.com/rpm-software-management/rpm/pull/1919 https://github.com/rpm-software-management/rpm/commit/96ec957e281220f8e137a2d5eb23b83a6377d556 This issue has been addressed in the following products: Red Hat Enterprise Linux 9.0 Extended Update Support Via RHSA-2024:0435 https://access.redhat.com/errata/RHSA-2024:0435 This issue has been addressed in the following products: Red Hat Enterprise Linux 9 Via RHSA-2024:0463 https://access.redhat.com/errata/RHSA-2024:0463 This issue has been addressed in the following products: Red Hat Enterprise Linux 9.2 Extended Update Support Via RHSA-2024:0453 https://access.redhat.com/errata/RHSA-2024:0453 This issue has been addressed in the following products: Red Hat Enterprise Linux 8.6 Extended Update Support Via RHSA-2024:0424 https://access.redhat.com/errata/RHSA-2024:0424 This issue has been addressed in the following products: Red Hat Enterprise Linux 8.8 Extended Update Support Via RHSA-2024:0582 https://access.redhat.com/errata/RHSA-2024:0582 This issue has been addressed in the following products: Red Hat Enterprise Linux 8 Via RHSA-2024:0647 https://access.redhat.com/errata/RHSA-2024:0647 |