Rogue backends can cause DoS of guests via high frequency events T[his CNA information…
Key facts
- Attack vector
- Local
- Privileges required
- Low
- User interaction
- None
- Attack complexity
- Low
- Impact type
- —
- Confidentiality · integrity · availability
- None · None · High
- Fix status
- Will not fix Red Hat: no fix planned
Attack profile from CVSS 3.1 · NVD. Fix status from CNA and Red Hat.
Summary
Rogue backends can cause DoS of guests via high frequency events T[his CNA information record relates to multiple CVEs; the text explains which aspects/vulnerabilities correspond to which CVE.] Xen offers the ability to run PV backends in regular unprivileged guests, typically referred to as "driver domains". Running PV backends in driver domains has one primary security advantage: if a driver domain gets compromised, it doesn't have the privileges to take over the system. However, a malicious driver domain could try to attack other guests via sending events at a high frequency leading to a Denial of Service in the guest due to trying to service interrupts for elongated amounts of time. There are three affected backends: * blkfront patch 1, CVE-2021-28711 * netfront patch 2, CVE-2021-28712 * hvc_xen (console) patch 3, CVE-2021-28713
Why it matters now
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 |
|---|---|---|---|---|---|
| Linux | Linux | — | — | No fix listed | CNA |
- Linux VendorLinux Affected — Fixed in — No fix listed CNA
CPE configurations NVD · 4
| CPE | Versions | Role | Vendor |
|---|---|---|---|
| cpe:2.3:o:xen:xen:-:*:*:*:*:*:*:* | not specified by NVD | Vulnerable | Xen |
| 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:o:xen:xen:-:*:*:*:*:*:*:* Versions not specified by NVD Vulnerable ·Xen
- 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
No fixed version listed by the sources yet.
Vendor assessments
Red Hat
Red Hat rating: Moderate. Red Hat's page for this CVE →
| Product | Status | Plan or fix |
|---|---|---|
| Red Hat Enterprise Linux 7 | Affected | No fix planned: Will not fix |
| Red Hat Enterprise Linux 8 | Affected | No fix planned: Will not fix |
| Red Hat Enterprise Linux 9 | Affected | No fix planned: Will not fix |
Not affected: 1 product
- Red Hat Enterprise Linux 6
Timeline
- 2026-10-02 Threatist record created from CVE-2021-28712
- 2026-10-03 Alias added: GHSA-9345-957r-vw5m
References
More Linux vulnerabilities
- TI-2025-26358 tls: fix handling of zero-length records on the rx_list KEVCVSS 3.1CRITICAL 9.8
- TI-2026-38352 netfilter: bridge: make ebt_snat ARP rewrite writable KEVCVSS 3.1HIGH 8.8
- TI-2021-02452 Incorrect authorization in Ubuntu linux kernel KEVCVSS 3.1HIGH 8.8
- TI-2013-05264 The (1) get_user and (2) put_user API functions in the Linux kernel before 3.5.5 on the… KEVCVSS 3.1HIGH 8.8
- TI-2022-00125 Integer overflow in kernel KEVCVSS 3.1HIGH 8.4
- TI-2013-01864 The perf_swevent_init function in kernel/events/core.c in the Linux kernel before 3.8.9… KEVCVSS 3.1HIGH 8.4
Sources
- CVE-2021-28712 · CVE Program
- CVE-2021-28712 · NVD
- FIRST EPSS
- GHSA-9345-957r-vw5m · GitHub Advisory Database · CC BY 4.0
- CVE-2021-28712 · Red Hat security data · CC BY 4.0
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences