Bug 1525761 (CVE-2017-17450) - CVE-2017-17450 kernel: Unchecked capabilities in net/netfilter/xt_osf.c allows for unprivileged modification to systemwide fingerprint list
Summary: CVE-2017-17450 kernel: Unchecked capabilities in net/netfilter/xt_osf.c allow...
Keywords:
Status: CLOSED WONTFIX
Alias: CVE-2017-17450
Product: Security Response
Classification: Other
Component: vulnerability
Version: unspecified
Hardware: All
OS: Linux
low
low
Target Milestone: ---
Assignee: Red Hat Product Security
QA Contact:
URL:
Whiteboard:
Depends On: 1525764
Blocks: 1525773
TreeView+ depends on / blocked
 
Reported: 2017-12-14 01:25 UTC by Sam Fowler
Modified: 2021-02-17 01:06 UTC (History)
42 users (show)

Fixed In Version:
Doc Type: Bug Fix
Doc Text:
net/netfilter/xt_osf.c in the Linux kernel through 4.14.4 does not require the CAP_NET_ADMIN capability for add_callback and remove_callback operations. This allows local users to bypass intended access restrictions because the xt_osf_fingers data structure is shared across all network namespaces.
Clone Of:
Environment:
Last Closed: 2018-01-25 10:30:55 UTC

Attachments (Terms of Use)

Description Sam Fowler 2017-12-14 01:25:57 UTC 
net/netfilter/xt_osf.c in the Linux kernel through 4.14.4 does not require the CAP_NET_ADMIN capability for add_callback and remove_callback operations, which allows local users to bypass intended access restrictions because the xt_osf_fingers data structure is shared across all network namespaces.

References:

https://lkml.org/lkml/2017/12/5/982

https://marc.info/?t=151251761200002&r=1&w=2

An upstream patch:

https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=916a27901de01446bcf57ecca4783f6cff493309
Comment 1 Sam Fowler 2017-12-14 01:48:42 UTC 
Created kernel tracking bugs for this issue:

Affects: fedora-all [bug 1525764]
Comment 4 Vladis Dronov 2018-01-24 16:38:40 UTC 
Statement:

This issue does not affect the Linux kernel packages as shipped with Red Hat Enterprise Linux 5 and Red Hat Enterprise MRG 2, as a code with the flaw is not present or is not built in the products listed.

This issue affects the versions of the Linux kernel as shipped with Red Hat Enterprise Linux 6, 7, its real-time kernel, Red Hat Enterprise Linux 7 for ARM 64 and Red Hat Enterprise Linux 7 for Power 9 LE. This has been rated as having Low security impact and is not currently planned to be addressed in future updates. For additional information, refer to the Red Hat Enterprise Linux Life Cycle: https://access.redhat.com/support/policy/updates/errata/.
Comment 5 Vladis Dronov 2018-01-24 16:39:25 UTC 
What is Red Hat Enterprise Linux 7 for ARM 64,
        Red Hat Enterprise Linux 7 for Power 9 LE

The kernel package as shipped with Red Hat Enterprise Linux 7 for ARM 64 and Red Hat Enterprise Linux 7 for Power 9 LE is an updated kernel intended to support new architectures not available at the time of Red Hat Enterprise Linux 7 original shipping. The new kernel version is based on an upstream Linux kernel version 4.11. The offering is distributed with other updated packages, but most of the userspace is the standard Red Hat Enterprise Linux 7 Server RPM files.

For more information please refer to:

https://access.redhat.com/articles/3158541
https://access.redhat.com/articles/3158511
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