Bug 921448 (CVE-2013-1858) - CVE-2013-1858 kernel: CLONE_NEWUSER | CLONE_FS chroot exploit
Summary: CVE-2013-1858 kernel: CLONE_NEWUSER | CLONE_FS chroot exploit
Keywords:
Status: CLOSED NOTABUG
Alias: CVE-2013-1858
Product: Security Response
Classification: Other
Component: vulnerability
Version: unspecified
Hardware: All
OS: Linux
high
high
Target Milestone: ---
Assignee: Red Hat Product Security
QA Contact:
URL:
Whiteboard:
Depends On:
Blocks: 921413
TreeView+ depends on / blocked
 
Reported: 2013-03-14 08:50 UTC by Prasad Pandit
Modified: 2021-02-17 07:55 UTC (History)
28 users (show)

Fixed In Version:
Doc Type: Bug Fix
Doc Text:
Clone Of:
Environment:
Last Closed: 2013-05-10 11:50:04 UTC

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Description Prasad Pandit 2013-03-14 08:50:15 UTC 
Linux kernels which support unprivileged user namespaces (CLONE_NEWUSER) and at the same time allow sharing file system information (CLONE_FS) between parent process and its newly clone(2)d child process in the new user namespace, are vulnerable to a privilege escalation flaw as presented by Sebastian Krahmer
in his chroot exploit [1].

  [1] http://stealth.openwall.net/xSports/clown-newuser.c

An unprivileged local user could use this flaw to gain root privileges on a system.

Upstream fix:
-------------
 -> https://git.kernel.org/linus/e66eded8309ebf679d3d3c1f5820d1f2ca332c71

Reference:
----------
 -> http://www.openwall.com/lists/oss-security/2013/03/13/8
Comment 1 Prasad Pandit 2013-03-14 08:56:09 UTC 
Statement:

This issue did not affect the versions of the Linux kernel as shipped with Red Hat Enterprise Linux 5, 6, and Red Hat Enterprise MRG 2.

This issue did not affect the versions of the Linux kernel as shipped with Fedora 17 and 18 as they were not built with CONFIG_USER_NS configuration option.
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