CVE-2009-3621

Exp

net/unix/af_unix.c in the Linux kernel 2.6.31.4 and earlier allows local users to cause a denial of service (system hang) by creating an abstract-namespace AF_UNIX listening socket, performing a shutdown operation on this socket, and then performing a series of connect operations to this socket.

Published: 2009-10-22 Last update: 2026-04-23 Assigner: [email protected] Source: [email protected]
NVD Status：Modified，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2009-3621 is rated Exploit Available (58.1/100): CVSS Medium severity, with medium exploitation likelihood (EPSS 0.99%). 5 public exploit reference(s) are indexed (Exploit-DB). Public exploits are available—assess exposure, apply mitigations, and prioritize patching.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Public exploit references (Exploit-DB) for CVE-2009-3621

EDB-ID Source Kind Published Link
10022 exploit_db edb 2009-11-10 Exploit-DB ↗
— nvd_ref exploit_tag Exploit-DB ↗
— nvd_ref exploit_tag Exploit-DB ↗
— nvd_ref exploit_tag Exploit-DB ↗
— nvd_ref exploit_tag Exploit-DB ↗

Exploit prediction scoring system (EPSS) score for CVE-2009-3621

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-06-15 0.06% 0.99% +0.92%
2 2026-01-23 0.04% 0.06% +0.02%
3 2023-03-07 — 0.04% —

Full EPSS history (4 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2009-3621

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
5.5 3.1 MEDIUM
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H Click to expand
Attack vector (AV:L)
They already need access on the box, or another person has to do something wrong; it’s not a remote drive-by.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:L)
A normal user session is enough; they don’t have to be admin.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:N)
Doesn’t really leak secrets in a meaningful way.
Integrity (I:N)
Data isn’t meaningfully altered or forged.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
 1.8 3.6 [email protected]
4.9 2.0 MEDIUM
AV:L/AC:L/Au:N/C:N/I:N/A:C Click to expand
Access vector (AV:L)
Requires local access to the target system.
Access complexity (AC:L)
Exploitation conditions are straightforward and predictable.
Authentication (AU:N)
No authentication is required.
Confidentiality impact (C:N)
No confidentiality impact.
Integrity impact (I:N)
No integrity impact.
Availability impact (A:C)
Complete availability impact.
 3.9 6.9 [email protected]

Weakness enumeration for CVE-2009-3621

OS Trackers for CVE-2009-3621

vendor priority summary link
redhat medium — https://access.redhat.com/security/cve/CVE-2009-3621
ubuntu low CVE-2009-3621 low priority: Ubuntu including 2 source packages (linux, linux-source-2.6.15), 12 status rows across 6 suites (dapper, hardy, intrepid, jaunty, karmic, upstream): DNE 5, released 5, needs-triage 2. https://ubuntu.com/security/CVE-2009-3621

Vendor comments (NVD) for CVE-2009-3621

  • Red Hat (2009-12-17T00:00:00)

    Red Hat is aware of this issue and is tracking it via the following bug: https://bugzilla.redhat.com/bugzilla/show_bug.cgi?id=CVE-2009-3621 This issue has been rated as having moderate security impact. It was addressed in Red Hat Enterprise Linux 4, 5 and Red Hat Enterprise MRG via: https://rhn.redhat.com/errata/RHSA-2009-1671.html , https://rhn.redhat.com/errata/RHSA-2009-1670.html and https://rhn.redhat.com/errata/RHSA-2009-1540.html respectively. This issue is not planned to be fixed in Red Hat Enterprise Linux 3, due to this product being in Production 3 of its maintenance life-cycle, where only qualified security errata of important or critical impact are addressed. For further information about Errata Support Policy, visit: http://www.redhat.com/security/updates/errata/

Affected software / configurations for CVE-2009-3621

Vendor Product Version Raw CPE
linux linux_kernel <= 2.6.31.4 cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
canonical ubuntu_linux 6.06 cpe:2.3:o:canonical:ubuntu_linux:6.06:*:*:*:*:*:*:*
canonical ubuntu_linux 8.04 cpe:2.3:o:canonical:ubuntu_linux:8.04:*:*:*:*:*:*:*
canonical ubuntu_linux 8.10 cpe:2.3:o:canonical:ubuntu_linux:8.10:*:*:*:*:*:*:*
canonical ubuntu_linux 9.04 cpe:2.3:o:canonical:ubuntu_linux:9.04:*:*:*:*:*:*:*
canonical ubuntu_linux 9.10 cpe:2.3:o:canonical:ubuntu_linux:9.10:*:*:*:*:*:*:*
fedoraproject fedora 10 cpe:2.3:o:fedoraproject:fedora:10:*:*:*:*:*:*:*
opensuse opensuse 11.0 cpe:2.3:o:opensuse:opensuse:11.0:*:*:*:*:*:*:*
opensuse opensuse 11.2 cpe:2.3:o:opensuse:opensuse:11.2:*:*:*:*:*:*:*
suse suse_linux_enterprise_desktop 10 cpe:2.3:o:suse:suse_linux_enterprise_desktop:10:sp2:*:*:*:*:*:*
suse suse_linux_enterprise_desktop 10 cpe:2.3:o:suse:suse_linux_enterprise_desktop:10:sp3:*:*:*:*:*:*
suse suse_linux_enterprise_server 10 cpe:2.3:o:suse:suse_linux_enterprise_server:10:sp2:*:*:*:*:*:*
suse suse_linux_enterprise_server 10 cpe:2.3:o:suse:suse_linux_enterprise_server:10:sp3:*:*:*:*:*:*
vmware vma 4.0 cpe:2.3:a:vmware:vma:4.0:*:*:*:*:*:*:*
vmware esx 4.0 cpe:2.3:o:vmware:esx:4.0:*:*:*:*:*:*:*

References for CVE-2009-3621

URL Tags
http://git.kernel.org/?p=linux/kernel/git/davem/net-2.6.git%3Ba=commit%3Bh=77238f2b942b38ab4e7f3aced44084493e4a8675
http://lists.opensuse.org/opensuse-security-announce/2009-12/msg00002.html Mailing List Third Party Advisory
http://lists.opensuse.org/opensuse-security-announce/2009-12/msg00005.html Mailing List Third Party Advisory
http://lists.opensuse.org/opensuse-security-announce/2010-01/msg00000.html Mailing List Third Party Advisory
http://lists.opensuse.org/opensuse-security-announce/2010-02/msg00005.html Mailing List Third Party Advisory
http://lists.opensuse.org/opensuse-security-announce/2010-02/msg00007.html Mailing List Third Party Advisory
http://lists.vmware.com/pipermail/security-announce/2010/000082.html Mailing List Third Party Advisory
http://lkml.org/lkml/2009/10/19/50 Mailing List Third Party Advisory
http://patchwork.kernel.org/patch/54678/ Exploit Mailing List Third Party Advisory
http://secunia.com/advisories/37086 Broken Link
http://secunia.com/advisories/37909 Broken Link
http://secunia.com/advisories/38017 Broken Link
http://secunia.com/advisories/38794 Broken Link
http://secunia.com/advisories/38834 Broken Link
http://www.mandriva.com/security/advisories?name=MDVSA-2009:329 Broken Link
http://www.openwall.com/lists/oss-security/2009/10/19/2 Exploit Mailing List Patch Third Party Advisory
http://www.openwall.com/lists/oss-security/2009/10/19/4 Exploit Mailing List Patch Third Party Advisory
http://www.redhat.com/support/errata/RHSA-2009-1670.html Broken Link
http://www.redhat.com/support/errata/RHSA-2009-1671.html Broken Link
http://www.ubuntu.com/usn/usn-864-1 Third Party Advisory
http://www.vupen.com/english/advisories/2010/0528 Broken Link
https://bugzilla.redhat.com/show_bug.cgi?id=529626 Exploit Issue Tracking Third Party Advisory
https://oval.cisecurity.org/repository/search/definition/oval%3Aorg.mitre.oval%3Adef%3A6895 Third Party Advisory
https://oval.cisecurity.org/repository/search/definition/oval%3Aorg.mitre.oval%3Adef%3A9921 Third Party Advisory
https://rhn.redhat.com/errata/RHSA-2009-1540.html Third Party Advisory
https://www.redhat.com/archives/fedora-package-announce/2009-November/msg00190.html Mailing List Third Party Advisory
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