CVE-2023-2861 | Qemu: 9pfs: improper access control on special files

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.

Published: 2023-12-06 Last update: 2024-11-21 Assigner: [email protected] Source: [email protected]
NVD Status：Modified，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2023-2861 is rated Low Risk (28.2/100): CVSS Medium severity, with low exploitation likelihood (EPSS 0.04%). Monitor for updates and reassess as exploit intelligence or EPSS changes.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2023-2861

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2025-11-21 0.06% 0.04% -0.02%
2 2025-11-18 0.03% 0.06% +0.03%
3 2025-04-15 — 0.03% —

Full EPSS history (5 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2023-2861

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
6.0 3.1 MEDIUM
CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:N Click to expand
Attack vector (AV:L)
They already need access on the box, or another person has to do something wrong; it’s not a remote drive-by.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:H)
They need powerful rights—admin, root, or similar—before this pays off.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:H)
Serious risk that confidential data gets exposed in a big way.
Integrity (I:H)
They could widely tamper with or forge data—trust in the data is badly hurt.
Availability (A:N)
Service keeps running; no real outage angle.
 0.8 5.2 [email protected]
7.1 3.1 HIGH
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N Click to expand
Attack vector (AV:L)
They already need access on the box, or another person has to do something wrong; it’s not a remote drive-by.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:L)
A normal user session is enough; they don’t have to be admin.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:H)
Serious risk that confidential data gets exposed in a big way.
Integrity (I:H)
They could widely tamper with or forge data—trust in the data is badly hurt.
Availability (A:N)
Service keeps running; no real outage angle.
 1.8 5.2 [email protected]

Weakness enumeration for CVE-2023-2861

OS Trackers for CVE-2023-2861

vendor priority summary link
alpine — CVE-2023-2861: 1 source package rows (qemu); 6 state rows across 6 repos (3.18-community, 3.19-community, 3.20-community, 3.21-community, 3.22-community, edge-community); fixed 6, open 0. https://security.alpinelinux.org/vuln/CVE-2023-2861
debian not yet assigned CVE-2023-2861 not yet assigned priority: Debian including 1 source packages (qemu), 5 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): resolved 4, open 1. https://security-tracker.debian.org/tracker/CVE-2023-2861
gentoo normal CVE-2023-2861: 1 GLSA(s) (202408-18), 1 atom(s) (app-emulation/qemu); latest impact normal. https://bugs.gentoo.org/buglist.cgi?quicksearch=CVE-2023-2861
redhat low — https://access.redhat.com/security/cve/CVE-2023-2861
suse high — https://www.suse.com/security/cve/CVE-2023-2861/
ubuntu low CVE-2023-2861 low priority: Ubuntu including 2 source packages (kvmtool, qemu), 20 status rows across 13 suites (bionic, focal, jammy, kinetic, lunar, mantic, noble, oracular, plucky, questing, trusty, upstream, xenial): released 7, not-affected 5, ignored 4, DNE 2, needs-triage 2. https://ubuntu.com/security/CVE-2023-2861

Affected software / configurations for CVE-2023-2861

Vendor Product Version Raw CPE
qemu qemu < 8.1.0 cpe:2.3:a:qemu:qemu:*:*:*:*:*:*:*:*

References for CVE-2023-2861

cvelogic Threat Intelligence