CVE-2018-13405

high-risk
Published 2018-07-06

The inode_init_owner function in fs/inode.c in the Linux kernel through 3.16 allows local users to create files with an unintended group ownership, in a scenario where a directory is SGID to a certain group and is writable by a user who is not a member of that group. Here, the non-member can trigger creation of a plain file whose group ownership is that group. The intended behavior was that the non-member can trigger creation of a directory (but not a plain file) whose group ownership is that group. The non-member can escalate privileges by making the plain file executable and SGID.

Do I need to act?

-
0.17% chance of exploitation
EPSS score — low exploit probability
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Not on CISA KEV list
No confirmed active exploitation reported to CISA
!
1 public exploit available
45033
?
Patch status unknown
Check vendor advisories for fix availability and mitigation guidance
7
CVSS 7.8/10 High
LOCAL / LOW complexity

Affected Products (20)

Affected Vendors

Debian Redhat Linux F5 Canonical Fedoraproject

References (56)

Patch http://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=0fa3ec...
Mailing List http://openwall.com/lists/oss-security/2018/07/13/2
Broken Link http://www.securityfocus.com/bid/106503
Third Party Advisory https://access.redhat.com/errata/RHSA-2018:2948
Third Party Advisory https://access.redhat.com/errata/RHSA-2018:3083
Third Party Advisory https://access.redhat.com/errata/RHSA-2018:3096
Third Party Advisory https://access.redhat.com/errata/RHSA-2019:0717
Third Party Advisory https://access.redhat.com/errata/RHSA-2019:2476
Third Party Advisory https://access.redhat.com/errata/RHSA-2019:2566
Third Party Advisory https://access.redhat.com/errata/RHSA-2019:2696
Third Party Advisory https://access.redhat.com/errata/RHSA-2019:2730
Third Party Advisory https://access.redhat.com/errata/RHSA-2019:4159
Third Party Advisory https://access.redhat.com/errata/RHSA-2019:4164
Mailing List https://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git/commit/?id=0b3369840...
Patch https://github.com/torvalds/linux/commit/0fa3ecd87848c9c93c2c828ef4c3a8ca36ce46c...
Third Party Advisory https://lists.debian.org/debian-lts-announce/2018/08/msg00014.html
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedorapro...
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedorapro...
Third Party Advisory https://support.f5.com/csp/article/K00854051
Third Party Advisory https://twitter.com/grsecurity/status/1015082951204327425
and 36 more references
59
/ 100
high-risk
Severity 24/34 · High
Exploitability 8/34 · Low
Exposure 27/34 · High