oss-sec mailing list archives
Re: CVE-2016-9602 Qemu: 9p: virtfs allows guest to access host filesystem
From: Greg Kurz <groug () kaod org>
Date: Tue, 17 Jan 2017 13:33:51 +0100
On Tue, 17 Jan 2017 17:48:59 +0530 (IST) P J P <ppandit () redhat com> wrote:
Hello, Quick Emulator(Qemu) built with the VirtFS, host directory sharing via Plan 9 File System(9pfs) support, is vulnerable to an improper link following issue. It could occur while accessing symbolic link files on a shared host directory. A privileged user inside guest could use this flaw to access host file system beyond the shared folder and potentially escalating their privileges on a host. Reference: ---------- -> http://wiki.qemu.org/Documentation/9psetup -> https://bugzilla.redhat.com/show_bug.cgi?id=1413929 Please see a proposed patch to fix this issue attached herein.
The proposed patch DOES NOT fix the vulnerability because of a TOCTTOU issue. Please ignore it. I'm working on another fix I hope to complete this week.
This issue was discovered by Jann Horn of Google Project Zero. 'CVE-2016-9602' has been assigned to this issue by Red Hat Inc. Thank you. -- Prasad J Pandit / Red Hat Product Security Team 47AF CE69 3A90 54AA 9045 1053 DD13 3D32 FE5B 041F
Current thread:
- CVE-2016-9602 Qemu: 9p: virtfs allows guest to access host filesystem P J P (Jan 17)
- Re: CVE-2016-9602 Qemu: 9p: virtfs allows guest to access host filesystem Greg Kurz (Jan 17)