Bug 2219266 (CVE-2023-2861)

Summary: CVE-2023-2861 QEMU: 9pfs: improper access control on special files
Product: [Other] Security Response Reporter: TEJ RATHI <trathi>
Component: vulnerabilityAssignee: Red Hat Product Security <security-response-team>
Status: CLOSED NOTABUG QA Contact:
Severity: low Docs Contact:
Priority: low    
Version: unspecifiedCC: ddepaula, jen, jferlan, jmaloy, knoel, mkenneth, mrezanin, mst, pbonzini, virt-maint, ymankad
Target Milestone: ---Keywords: Security
Target Release: ---   
Hardware: All   
OS: Linux   
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.
Story Points: ---
Clone Of: Environment:
Last Closed: 2023-07-04 07:46:01 UTC Type: ---
Regression: --- Mount Type: ---
Documentation: --- CRM:
Verified Versions: Category: ---
oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
Cloudforms Team: --- Target Upstream Version:
Bug Depends On: 2219306    
Bug Blocks: 2175653    

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.


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):