What is CVE-2009-3640?

CVE-2009-3640 is a Medium severity Linux kernel vulnerability with a CVSS score of 4.9 out of 10, classified as a Improper Input Validation flaw (CWE-20). CVE-2009-3640 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.

What is the CVSS score for CVE-2009-3640?

CVE-2009-3640 has a CVSS score of 4.9 out of 10, rated Medium severity. The vector string is AV:L/AC:L/Au:N/C:N/I:N/A:C.

Is there a patch available for CVE-2009-3640?

No patch is currently available for CVE-2009-3640. Monitor the NIST NVD and your Linux distribution's security advisories for updates.

Is CVE-2009-3640 actively exploited?

CVE-2009-3640 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.

CVE-2009-3640

Medium

The update_cr8_intercept function in arch/x86/kvm/x86.c in the KVM subsystem in the Linux kernel before 2.6.32-rc1 does not properly handle the absence of an Advanced Programmable Interrupt Controller (APIC), which allows local users to cause a denial of service (NULL pointer dereference and system crash) or possibly gain privileges via a call to the kvm_vcpu_ioctl function.

Package Linux Kernel

Published 2009-10-29

Last modified 2026-04-23

CVSS version 2.0

Patch available

Awaiting data

CVSS 2.0 score

4.9

out of 10

Medium

Attack Vector

Local

Attack Complexity

Low

Privileges Required

User Interaction

Scope

Confidentiality

Low

Integrity

None

Availability

Vector string

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

Weakness type

CWE-20

CVE-2009-3640 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-2009-3640 including vendor advisories, patch commits, exploit details, and third-party analysis. Links are sourced from the NIST NVD database.

Marc
http://marc.info/?l=oss-security&m=125626965020571&w=2
Marc
http://marc.info/?l=oss-security&m=125640417219385&w=2
Kernel.org
http://www.kernel.org/pub/linux/kernel/v2.6/testing/ChangeLog-2.6.32-rc1

Vendor Advisory
Securityfocus
http://www.securityfocus.com/bid/36805
Exchange
https://exchange.xforce.ibmcloud.com/vulnerabilities/53947
Kernel patch commit
http://git.kernel.org/?p=linux/kernel/git/torvalds/linux-2.6.git%3Ba=commit%3Bh=88c808fd42b53a7e01a2ac3253ef31fef74cb5af
Patch

Details

CVE ID CVE-2009-3640

Severity Medium

CVSS score 4.9 / 10

CVSS version 2.0

Published 2009-10-29

Modified 2026-04-23

KEV No

Patch Awaiting data

Package linux

Frequently asked questions

What is CVE-2009-3640?

CVE-2009-3640 is a Medium severity Linux kernel vulnerability with a CVSS score of 4.9 out of 10 , classified as an Improper Input Validation flaw (CWE-20) . CVE-2009-3640 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.
What is the CVSS score for CVE-2009-3640?

CVE-2009-3640 has a CVSS score of 4.9 out of 10, rated Medium severity (CVSS 2.0). The vector string is AV:L/AC:L/Au:N/C:N/I:N/A:C.
Is there a patch available for CVE-2009-3640?

No patch is currently available for CVE-2009-3640. Monitor the NIST NVD and your Linux distribution's security advisories for updates.
Is CVE-2009-3640 actively exploited?

No — CVE-2009-3640 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 →