Bug 2219266 (CVE-2023-2861) - CVE-2023-2861 QEMU: 9pfs: improper access control on special files
Summary: CVE-2023-2861 QEMU: 9pfs: improper access control on special files
Keywords:
Status: CLOSED NOTABUG
Alias: CVE-2023-2861
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: 2219306
Blocks: 2175653
TreeView+ depends on / blocked
 
Reported: 2023-07-03 06:57 UTC by TEJ RATHI
Modified: 2024-02-13 16:37 UTC (History)
11 users (show)

Fixed In Version: qemu-kvm 8.1.0
Doc Type: If docs needed, set a value
Doc Text:
A flaw was found in the 9p passthrough filesystem (9pfs) implementation in QEMU. The 9pfs server did not prohibit opening special files on the host side, potentially allowing a malicious client to escape from the exported 9p tree by creating and opening a device file in the shared folder.
Clone Of:
Environment:
Last Closed: 2023-07-04 07:46:01 UTC
Embargoed:

Attachments (Terms of Use)

Description TEJ RATHI 2023-07-03 06:57:40 UTC 
The 9p protocol does not specifically define how server shall behave when client tries to open a special file, however from security POV it does make sense for 9p server to prohibit opening any special file on host side in general. A sane Linux 9p client for instance would never attempt to open a special file on host side, it would always handle those exclusively on its guest side. A malicious client however could potentially escape from the exported 9p tree by creating and opening a device file on host side.

https://gitlab.com/qemu-project/qemu/-/commit/f6b0de53fb87ddefed348a39284c8e2f28dc4eda
Comment 1 Mauro Matteo Cascella 2023-07-03 08:03:12 UTC 
Created qemu tracking bugs for this issue:

Affects: fedora-all [bug 2219306]
Comment 2 Product Security DevOps Team 2023-07-04 07:45:59 UTC 
This bug is now closed. Further updates for individual products will be reflected on the CVE page(s):

https://access.redhat.com/security/cve/cve-2023-2861
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