CVE-2023-1386: Qemu: 9pfs: suid/sgid bits not dropped on file write

Severity: high (CVSS 7.8 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.2% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2023-07-24 · updated 2026-06-17
Weakness: CWE-281

Description

A flaw was found in the 9p passthrough filesystem (9pfs) implementation in QEMU. When a local user in the guest writes an executable file with SUID or SGID, none of these privileged bits are correctly dropped. As a result, in rare circumstances, this flaw could be used by malicious users in the guest to elevate their privileges within the guest and help a host local user to elevate privileges on the host.

Affected products

Fedoraproject Fedora: 38
QEMU: all versions

References

https://access.redhat.com/security/cve/CVE-2023-1386
https://bugzilla.redhat.com/show_bug.cgi?id=2223985
https://github.com/advisories/GHSA-ppj8-867g-rgjr
https://github.com/v9fs/linux/issues/29
https://security.netapp.com/advisory/ntap-20230831-0005/
https://access.redhat.com/security/cve/CVE-2023-1386
https://bugzilla.redhat.com/show_bug.cgi?id=2223985
https://github.com/advisories/GHSA-ppj8-867g-rgjr
https://github.com/v9fs/linux/issues/29
https://security.netapp.com/advisory/ntap-20230831-0005/

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