A flaw was found in the USB redirector device emulation of QEMU in versions prior to…
Priority MEDIUM 42CWE-763Published · Updated
Key facts
- Attack vector
- Network
- Privileges required
- Low
- User interaction
- None
- Attack complexity
- High
- Impact type
- —
- Confidentiality · integrity · availability
- High · High · High
- Fix status
- Partial Red Hat: 5 fixed, 5 without a fix
Attack profile from CVSS 3.1 · NVD. Fix status from CNA and Red Hat.
Summary
A flaw was found in the USB redirector device emulation of QEMU in versions prior to 6.1.0-rc2. It occurs when dropping packets during a bulk transfer from a SPICE client due to the packet queue being full. A malicious SPICE client could use this flaw to make QEMU call free() with faked heap chunk metadata, resulting in a crash of QEMU or potential code execution with the privileges of the QEMU process on the host.
Why it matters now
EPSS 0.0288 86th percentileScored 2026-11-08
Fix Partial Red Hat: 3 advisoriesRed Hat: 5 fixed, 5 without a fix
SSVC decision points
Not available: CISA has not published SSVC decision points for this record.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| — | QEMU | qemu 6.1.0-rc2 | — | No fix listed | CNA |
- QEMU Vendor— Affected qemu 6.1.0-rc2 Fixed in — No fix listed CNA
CPE configurations NVD · 7
| CPE | Versions | Role | Vendor |
|---|---|---|---|
| cpe:2.3:a:qemu:qemu:*:*:*:*:*:*:*:* | before 6.1.0 | Vulnerable | QEMU |
| cpe:2.3:a:qemu:qemu:6.1.0:rc1:*:*:*:*:*:* | 6.1.0 rc1 | Vulnerable | QEMU |
| cpe:2.3:o:redhat:enterprise_linux:8.0:*:*:*:-:*:*:* | 8.0 | Vulnerable | Red Hat |
| cpe:2.3:o:redhat:enterprise_linux:8.0:*:*:*:advanced_virtualization:*:*:* | 8.0 | Vulnerable | Red Hat |
| cpe:2.3:o:debian:debian_linux:9.0:*:*:*:*:*:*:* | 9.0 | Vulnerable | Debian |
| cpe:2.3:o:debian:debian_linux:10.0:*:*:*:*:*:*:* | 10.0 | Vulnerable | Debian |
| cpe:2.3:o:debian:debian_linux:11.0:*:*:*:*:*:*:* | 11.0 | Vulnerable | Debian |
- cpe:2.3:a:qemu:qemu:*:*:*:*:*:*:*:* Versions before 6.1.0 Vulnerable ·QEMU
- cpe:2.3:a:qemu:qemu:6.1.0:rc1:*:*:*:*:*:* Versions 6.1.0 rc1 Vulnerable ·QEMU
- cpe:2.3:o:redhat:enterprise_linux:8.0:*:*:*:-:*:*:* Versions 8.0 Vulnerable ·Red Hat
- cpe:2.3:o:redhat:enterprise_linux:8.0:*:*:*:advanced_virtualization:*:*:* Versions 8.0 Vulnerable ·Red Hat
- cpe:2.3:o:debian:debian_linux:9.0:*:*:*:*:*:*:* Versions 9.0 Vulnerable ·Debian
- cpe:2.3:o:debian:debian_linux:10.0:*:*:*:*:*:*:* Versions 10.0 Vulnerable ·Debian
- cpe:2.3:o:debian:debian_linux:11.0:*:*:*:*:*:*:* Versions 11.0 Vulnerable ·Debian
Remediation
Red Hat 3 advisories
- RHSA-2022:1759 Released 2022-05-10 · Red Hat rating Moderatevirt:rhel and virt-devel:rhel security, bug fix, and enhancement update
- Red Hat Enterprise Linux AppStream (v. 8) SLOF-20210217-1.module+el8.6.0+14480+c0a3aa0f.noarch::virt:rhel, SLOF-20210217-1.module+el8.6.0+14480+c0a3aa0f.src::virt:rhel, hivex-1.3.18-23.module+el8.6.0+14480+c0a3aa0f.aarch64::virt:rhel +47
- Red Hat Enterprise Linux CRB (v. 8) SLOF-20210217-1.module+el8.6.0+14480+c0a3aa0f.src::virt-devel:rhel, hivex-1.3.18-23.module+el8.6.0+14480+c0a3aa0f.i686::virt-devel:rhel, hivex-devel-1.3.18-23.module+el8.6.0+14480+c0a3aa0f.i686::virt-devel:rhel +47
- RHSA-2021:3704 Released 2021-09-30 · Red Hat rating Moderatevirt:8.2 and virt-devel:8.2 security update
- Advanced Virtualization CodeReady Builder for RHEL 8.2.1 SLOF-20191022-3.git899d9883.module+el8.2.0+5449+efc036dd.src::virt-devel:8.2, hivex-1.3.18-20.module+el8.2.0+5588+63a201c3.i686::virt-devel:8.2, hivex-devel-1.3.18-20.module+el8.2.0+5588+63a201c3.i686::virt-devel:8.2 +47
- Advanced Virtualization for RHEL 8.2.1 SLOF-20191022-3.git899d9883.module+el8.2.0+5449+efc036dd.noarch::virt:8.2, SLOF-20191022-3.git899d9883.module+el8.2.0+5449+efc036dd.src::virt:8.2, hivex-1.3.18-20.module+el8.2.0+5588+63a201c3.aarch64::virt:8.2 +47
- RHSA-2021:3703 Released 2021-09-30 · Red Hat rating Moderatevirt:av and virt-devel:av security and bug fix update
- Advanced Virtualization for RHEL 8.4.0.Z SLOF-20200717-1.gite18ddad8.module+el8.4.0+8855+a9e237a9.noarch::virt:av, SLOF-20200717-1.gite18ddad8.module+el8.4.0+8855+a9e237a9.src::virt-devel:av, SLOF-20200717-1.gite18ddad8.module+el8.4.0+8855+a9e237a9.src::virt:av +47
Vendor assessments
Red Hat
Red Hat rating: Moderate. Red Hat's page for this CVE →
| Product | Status | Plan or fix |
|---|---|---|
| Red Hat Enterprise Linux 6 | Affected | No fix planned: Out of support scope |
| Red Hat Enterprise Linux 7 | Affected | No fix planned: Out of support scope |
| Red Hat Enterprise Linux 8 Advanced Virtualization | Affected | No fix yet |
| Red Hat OpenStack Platform 10 (Newton) | Affected | No fix planned: Out of support scope |
| Red Hat OpenStack Platform 13 (Queens) | Affected | No fix planned: Out of support scope |
| Advanced Virtualization CodeReady Builder for RHEL 8.2.1 | Fixed | RHSA-2021:3704 |
| Advanced Virtualization for RHEL 8.2.1 | Fixed | RHSA-2021:3704 |
| Advanced Virtualization for RHEL 8.4.0.Z | Fixed | RHSA-2021:3703 |
| Red Hat Enterprise Linux AppStream (v. 8) | Fixed | RHSA-2022:1759 |
| Red Hat Enterprise Linux CRB (v. 8) | Fixed | RHSA-2022:1759 |
Not affected: 1 product
- Red Hat Enterprise Linux 9
Timeline
- 2026-10-02 Threatist record created from CVE-2021-3682
- 2026-10-03 Alias added: GHSA-2w4j-r5v6-3vgr
- 2026-10-30 Fix available: RHSA-2022:1759 · Red Hat
- 2026-10-30 Fix available: Red Hat Enterprise Linux AppStream (v. 8), Red Hat Enterprise Linux CRB (v. 8) · Red Hat
References
Sources
- CVE-2021-3682 · CVE Program
- CVE-2021-3682 · NVD
- FIRST EPSS
- GHSA-2w4j-r5v6-3vgr · GitHub Advisory Database · CC BY 4.0
- CVE-2021-3682 · Red Hat security data · CC BY 4.0
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