What is CVE-2009-4031?

CVE-2009-4031 is a High severity Linux kernel vulnerability with a CVSS score of 7.8 out of 10, classified as a Improper Input Validation flaw (CWE-20). CVE-2009-4031 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.

What is the CVSS score for CVE-2009-4031?

CVE-2009-4031 has a CVSS score of 7.8 out of 10, rated High severity. The vector string is AV:N/AC:L/Au:N/C:N/I:N/A:C.

Is there a patch available for CVE-2009-4031?

No patch is currently available for CVE-2009-4031. Monitor the NIST NVD and your Linux distribution's security advisories for updates.

Is CVE-2009-4031 actively exploited?

CVE-2009-4031 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.

CVE-2009-4031

High

The do_insn_fetch function in arch/x86/kvm/emulate.c in the x86 emulator in the KVM subsystem in the Linux kernel before 2.6.32-rc8-next-20091125 tries to interpret instructions that contain too many bytes to be valid, which allows guest OS users to cause a denial of service (increased scheduling latency) on the host OS via unspecified manipulations related to SMP support.

Package Linux Kernel

Published 2009-11-29

Last modified 2026-04-23

CVSS version 2.0

Patch available

Awaiting data

CVSS 2.0 score

7.8

out of 10

High

Attack Vector

Network

Attack Complexity

Low

Privileges Required

User Interaction

Scope

Confidentiality

Low

Integrity

None

Availability

Vector string

AV:N/AC:L/Au:N/C:N/I:N/A:C

Weakness type

CWE-20

CVE-2009-4031 is a Improper Input Validation vulnerability

What is Improper Input Validation?

The product receives input but does not validate it correctly, allowing attackers to craft inputs that cause unexpected behavior. Learn more on MITRE CWE

References

The following references provide additional information about CVE-2009-4031 including vendor advisories, patch commits, exploit details, and third-party analysis. Links are sourced from the NIST NVD database.

Lists
http://lists.opensuse.org/opensuse-security-announce/2010-03/msg00006.html

Third Party Advisory
Secunia
http://secunia.com/advisories/37720

Third Party Advisory
Openwall
http://www.openwall.com/lists/oss-security/2009/11/25/1

Mailing List Third Party Advisory
Openwall
http://www.openwall.com/lists/oss-security/2009/11/25/3

Mailing List Third Party Advisory
Securityfocus
http://www.securityfocus.com/bid/37130

Third Party Advisory VDB Entry
Red Hat
https://bugzilla.redhat.com/show_bug.cgi?id=541160

Issue Tracking Third Party Advisory
Oval
https://oval.cisecurity.org/repository/search/definition/oval%3Aorg.mitre.oval%3Adef%3A11089

Third Party Advisory
Red Hat
https://www.redhat.com/archives/fedora-package-announce/2009-December/msg00777.html

Third Party Advisory
Kernel patch commit
http://git.kernel.org/?p=linux/kernel/git/avi/kvm.git%3Ba=commit%3Bh=e42d9b8141d1f54ff72ad3850bb110c95a5f3b88
Patch
Kernel patch commit
http://www.kernel.org/pub/linux/kernel/v2.6/next/patch-v2.6.32-rc8-next-20091125.gz
Patch

Details

CVE ID CVE-2009-4031

Severity High

CVSS score 7.8 / 10

CVSS version 2.0

Published 2009-11-29

Modified 2026-04-23

KEV No

Patch Awaiting data

Package linux

Frequently asked questions

What is CVE-2009-4031?

CVE-2009-4031 is a High severity Linux kernel vulnerability with a CVSS score of 7.8 out of 10 , classified as an Improper Input Validation flaw (CWE-20) . CVE-2009-4031 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.
What is the CVSS score for CVE-2009-4031?

CVE-2009-4031 has a CVSS score of 7.8 out of 10, rated High severity (CVSS 2.0). The vector string is AV:N/AC:L/Au:N/C:N/I:N/A:C.
Is there a patch available for CVE-2009-4031?

No patch is currently available for CVE-2009-4031. Monitor the NIST NVD and your Linux distribution's security advisories for updates.
Is CVE-2009-4031 actively exploited?

No — CVE-2009-4031 has not been confirmed as actively exploited. It is not listed in the CISA Known Exploited Vulnerabilities (KEV) catalog.
What is Improper Input Validation (CWE-20)?

The product receives input but does not validate it correctly, allowing attackers to craft inputs that cause unexpected behavior. View CWE-20 on MITRE CWE →