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CVE-2009-4020

24
FAUCET Score

CVE-2009-4020 describes a stack-based buffer overflow vulnerability in the hfs subsystem of the Linux kernel, specifically affecting versions up to 2.6.32. This flaw, located in the hfs_readdir function, allows remote attackers to cause a denial of service or potentially execute arbitrary code through a specially crafted Hierarchical File System (HFS) filesystem. With a CVSS score of 7.8, it is considered high severity, indicating a remotely exploitable vulnerability with low attack complexity and a complete impact on availability. There is no evidence of active exploitation, public exploit code (Metasploit, Nuclei, ExploitDB), or significant community discussion surrounding this CVE.

Impacted Technologies

VendorProductVersion(s)CPE
2.6.32CPE matchmatch criteria
cpe:2.3:o:linux:linux_kernel:2.6.32:*:*:*:*:*:*:*

CVSS Data

CVSS version used by this source: 2.0

7.8HIGH

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

Confidentiality Impact
NONE
Integrity Impact
NONE
Availability Impact
COMPLETE
Access Vector
NETWORK
Access Complexity
LOW
Authentication
NONE
Exploitability Score
10.0
Impact Score
6.9
CvssVersion
2.0

Exploit Intelligence

EPSS Score
4.95%
Probability of exploitation in next 30 days
EPSS Percentile
91.3%
Percentile rank of EPSS score among Peer Group
As of 2026-07-28
Model: v2026.06.15
This CVE's current EPSS score of 0.0495 is in the 85th percentile among its peer group of 51,553 CVEs.

Social Chatter

The average CVE in this peer group has 0.0 Twitter, 0.0 Reddit, 0.1 Bluesky, 0.1 Mastodon, and 0.4 GitHub mentions.

Media Mentions

No media coverage found for this CVE.

The average CVE in this peer group has 0.1 InfoSec Media, 0.0 Vendor Blog, and 0.0 Security Researcher mentions.

Remediation

Patch Available

Vendor Patches (2)

redhatpatch availablevia redhat_api
Product: Red Hat Enterprise Linux 4Fixed in: kernel-0:2.6.9-89.0.20.EL
View patch
redhatpatch availablevia redhat_api
Product: Red Hat Enterprise Linux 5Fixed in: kernel-0:2.6.18-164.11.1.el5
View patch

Vendor Advisories (1)

redhatCVE-2009-4020Low

kernel: hfs buffer overflow

Dec 4, 2009

References

lists.opensuse.org / opensuse-security-announce/2010-01/msg00005.html
lists.opensuse.org / opensuse-security-announce/2010-03/msg00007.html
marc.info
bugzilla.redhat.com / show_bug.cgi
secunia.com / advisories/38276
secunia.com / advisories/39742
oval.cisecurity.org / repository/search/definition/oval%3Aorg.mitre.oval%3Adef%3A10091
oval.cisecurity.org / repository/search/definition/oval%3Aorg.mitre.oval%3Adef%3A6750
rhn.redhat.com / errata/RHSA-2010-0046.html
rhn.redhat.com / errata/RHSA-2010-0095.html
support.avaya.com / css/P8/documents/100073666
userweb.kernel.org / ~akpm/mmotm/broken-out/hfs-fix-a-potential-buffer-overflow.patch
Patch
debian.org / security/2010/dsa-2005
novell.com / linux/security/advisories/2010_23_kernel.html
openwall.com / lists/oss-security/2009/12/04/1