What is CVE-2009-4020?

CVE-2009-4020 is a High severity Linux kernel vulnerability with a CVSS score of 7.8 out of 10, classified as a Buffer Overflow flaw (CWE-119). CVE-2009-4020 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.

What is the CVSS score for CVE-2009-4020?

CVE-2009-4020 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-2009-4020?

No patch is currently available for CVE-2009-4020. Monitor the NIST NVD and your Linux distribution's security advisories for updates.

Is CVE-2009-4020 actively exploited?

CVE-2009-4020 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.

What is Buffer Overflow (CWE-119)?

The product performs operations on a memory buffer but reads or writes outside its intended boundaries. See MITRE CWE for full details: https://cwe.mitre.org/data/definitions/119.html

CVE-2009-4020

High

Stack-based buffer overflow in the hfs subsystem in the Linux kernel 2.6.32 allows remote attackers to have an unspecified impact via a crafted Hierarchical File System (HFS) filesystem, related to the hfs_readdir function in fs/hfs/dir.c.

Package Linux Kernel

Published 2009-12-04

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-119

CVE-2009-4020 is a Buffer Overflow vulnerability

What is Buffer Overflow?

The product performs operations on a memory buffer but reads or writes outside its intended boundaries. Learn more on MITRE CWE

References

The following references provide additional information about CVE-2009-4020 including vendor advisories, patch commits, exploit details, and third-party analysis. Links are sourced from the NIST NVD database.

Details

CVE ID CVE-2009-4020

Severity High

CVSS score 7.8 / 10

CVSS version 2.0

Published 2009-12-04

Modified 2026-04-23

KEV No

Patch Awaiting data

Package linux

Frequently asked questions

What is CVE-2009-4020?

CVE-2009-4020 is a High severity Linux kernel vulnerability with a CVSS score of 7.8 out of 10 , classified as a Buffer Overflow flaw (CWE-119) . CVE-2009-4020 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.
What is the CVSS score for CVE-2009-4020?

CVE-2009-4020 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-2009-4020?

No patch is currently available for CVE-2009-4020. Monitor the NIST NVD and your Linux distribution's security advisories for updates.
Is CVE-2009-4020 actively exploited?

No — CVE-2009-4020 has not been confirmed as actively exploited. It is not listed in the CISA Known Exploited Vulnerabilities (KEV) catalog.
What is Buffer Overflow (CWE-119)?

The product performs operations on a memory buffer but reads or writes outside its intended boundaries. View CWE-119 on MITRE CWE →