CVE-2021-4093
Last modified
CVE-2021-4093 is a high-severity vulnerability rated 8.8/10 on the CVSS scale. A flaw was found in the KVM's AMD code for supporting the Secure Encrypted Virtualization-Encrypted State (SEV-ES). A KVM guest using SEV-ES can trigger out-of-bounds reads and writes in the host kernel via a malicious VMGEXIT for a string I/O instruction (for example, outs or ins) using the exit reason SVM_EXIT_IOIO. EPSS estimates a 0.42% chance of exploitation in the next 30 days.
Description
A flaw was found in the KVM's AMD code for supporting the Secure Encrypted Virtualization-Encrypted State (SEV-ES). A KVM guest using SEV-ES can trigger out-of-bounds reads and writes in the host kernel via a malicious VMGEXIT for a string I/O instruction (for example, outs or ins) using the exit reason SVM_EXIT_IOIO. This issue results in a crash of the entire system or a potential guest-to-host escape scenario.
Metrics
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H
Weakness Enumeration
Affected Software
| Vendor | Product | Versions |
|---|---|---|
| Linux | Linux Kernel | >= 5.11, < 5.14.16 |
| Redhat | Enterprise Linux | 8.0 |
| Fedoraproject | Fedora | 35 |
| Canonical | Ubuntu Linux | 20.04 |
| Canonical | Ubuntu Linux | 21.10 |
References
- https://bugs.chromium.org/p/project-zero/issues/detail?id=2222Exploit, Mailing List, Patch, Third Party Advisory
- https://bugzilla.redhat.com/show_bug.cgi?id=2028584Issue Tracking, Patch, Third Party Advisory
- https://bugs.chromium.org/p/project-zero/issues/detail?id=2222Exploit, Mailing List, Patch, Third Party Advisory
- https://bugzilla.redhat.com/show_bug.cgi?id=2028584Issue Tracking, Patch, Third Party Advisory
Timeline
- Published
- Last Modified
- Status
- Modified
Frequently Asked Questions
What is CVE-2021-4093?
How severe is CVE-2021-4093?
How do I fix CVE-2021-4093?
How Strix Helps
- How Strix found a critical auth bypass in etcdStrix autonomously discovered a critical authentication bypass in etcd, later designated CVE-2026-33413.
- Autonomous PentestingAI agents that find and validate exploitable vulnerabilities like this one across your applications.
- PR ReviewsPentest every pull request so vulnerable code is caught before it ships to production.
- AI Penetration TestingHow AI-driven penetration testing continuously covers your attack surface.
Related CVEs from 2021
- CVE-2021-40923Cross-site scripting (XSS) vulnerability in install/index.ph…6.1
- CVE-2021-40924Cross-site scripting (XSS) vulnerability in install/index.ph…6.1
- CVE-2021-40925Cross-site scripting (XSS) vulnerability in dompdf/dompdf/ww…6.1
- CVE-2021-40926Cross-site scripting (XSS) vulnerability in demos/demo.mysql…6.1
- CVE-2021-40927Cross-site scripting (XSS) vulnerability in callback.php in …6.1
- CVE-2021-40928Cross-site scripting (XSS) vulnerability in index.php in Fle…6.1
- CVE-2021-40940Monstra 3.0.4 does not filter the case of php, which leads t…9.8
- CVE-2021-40941In Bento4 1.6.0-638, there is an allocator is out of memory …7.5
- CVE-2021-40942In GPAC MP4Box v1.1.0, there is a heap-buffer-overflow in th…5.5
- CVE-2021-40943In Bento4 1.6.0-638, there is a null pointer reference in th…5.5
- CVE-2021-40944In GPAC MP4Box 1.1.0, there is a Null pointer reference in t…5.5
- CVE-2021-4095A NULL pointer dereference was found in the Linux kernel's K…5.5
Are you affected by CVE-2021-4093?
Run a free Strix scan to check your systems for this vulnerability.
Scan your code nowSource: NVD / NIST