Bug 1213501 (CVE-2023-1386)

Summary: VUL-0: CVE-2023-1386: kvm,qemu: QEMU: 9pfs: SUID/SGID bits not dropped on file write
Product: [Novell Products] SUSE Security Incidents Reporter: Robert Frohl <rfrohl>
Component: IncidentsAssignee: E-mail List <kvm-bugs>
Status: NEW --- QA Contact: Security Team bot <security-team>
Severity: Normal    
Priority: P3 - Medium CC: dfaggioli, security-team
Version: unspecified   
Target Milestone: ---   
Hardware: Other   
OS: Other   
URL: https://smash.suse.de/issue/372982/
Whiteboard: CVSSv3.1:SUSE:CVE-2023-1386:3.3:(AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:N)
Found By: Security Response Team Services Priority:
Business Priority: Blocker: ---
Marketing QA Status: --- IT Deployment: ---

Description Robert Frohl 2023-07-20 06:58:57 UTC 
CVE-2023-1386

A flaw was discovered in 9pfs. Jietao Xiao and his team found that when a local user in the guest tries to write an executable file with SUID or SGID, none of these privileged bits are correctly dropped. As a result, in rare circumstances(exist an executable file owned by root, writable by others, has SUID/SGID bits), this flaw could be used by malicious users in the guest to elevate their privileges within the guest and help a host's local user to elevate privileges on the host.

Upstream issue:
https://github.com/v9fs/linux/issues/29

References:
http://web.nvd.nist.gov/view/vuln/detail?vulnId=CVE-2023-1386
https://bugzilla.redhat.com/show_bug.cgi?id=2223985