Vulnerability in Linux
CVE-2021-28711
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
EPSS: 0.003 (25.7th percentile) — read the EPSS interpretation.
CVSS v3 metric
CVSS v3 base score 6.5 (Medium). Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:N/I:N/A:H.
Affected products
- Linux — versions consult Xen advisory XSA-391
- Xen
- Debian Debian_linux — versions 9.0, 10.0, 11.0
Public proof-of-concept exploits
References
- security@xen.org (Patch, x_refsource_MISC, Vendor Advisory)
- security@xen.org (vendor-advisory, Third Party Advisory, x_refsource_DEBIAN)
- security@xen.org (mailing-list, x_refsource_MLIST, Third Party Advisory)
- security@xen.org (mailing-list, x_refsource_MLIST, Third Party Advisory)
- security@xen.org (vendor-advisory, Third Party Advisory, x_refsource_DEBIAN)
Frequently asked questions
- What is CVE-2021-28711?
- CVE-2021-28711 is a medium-severity vulnerability in Linux. CVSS score: 6.5/10. Published 2022-01-05.
- How severe is CVE-2021-28711?
- Medium severity. CVSS v3 base score is 6.5 out of 10.
- Is CVE-2021-28711 known to be exploited?
- 1 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.