CVE-2009-0692

CVE-2009-0692 is a critical-severity vulnerability in Isc Dhcp with a CVSS 2.0 base score of 10.0. Its EPSS exploit-prediction score of 26% places it in the 98th percentile, indicating an elevated likelihood of exploitation. The underlying weakness is classified as CWE-119.

Key facts

• Severity: Critical (CVSS 2.0 base score 10.0)
• EPSS exploit prediction: 26% (98th percentile)
• Actively exploited: Not listed in CISA KEV
• Weakness: CWE-119
• Affected product: Isc Dhcp
• Published: 2009-07-14
• Last modified: 2026-06-16

Description

Stack-based buffer overflow in the script_write_params method in client/dhclient.c in ISC DHCP dhclient 4.1 before 4.1.0p1, 4.0 before 4.0.1p1, 3.1 before 3.1.2p1, 3.0, and 2.0 allows remote DHCP servers to execute arbitrary code via a crafted subnet-mask option.

Frequently asked questions

What is CVE-2009-0692?

Stack-based buffer overflow in the script_write_params method in client/dhclient.c in ISC DHCP dhclient 4.1 before 4.1.0p1, 4.0 before 4.0.1p1, 3.1 before 3.1.2p1, 3.0, and 2.0 allows remote DHCP servers to execute arbitrary code via a crafted subnet-mask option.

How severe is CVE-2009-0692?

CVE-2009-0692 has a CVSS 2.0 base score of 10.0, rated critical severity.

Is CVE-2009-0692 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 26% (98th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2009-0692?

CVE-2009-0692 primarily affects Isc Dhcp. In total, 5 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2009-0692?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its critical severity, prioritise patching exposed systems.

When was CVE-2009-0692 published?

CVE-2009-0692 was published on 2009-07-14 and last updated on 2026-06-16.

References

• http://ftp.netbsd.org/pub/NetBSD/security/advisories/NetBSD-SA2009-010.txt.asc
• http://itrc.hp.com/service/cki/docDisplay.do?docId=emr_na-c02286083
• http://lists.opensuse.org/opensuse-security-announce/2009-07/msg00003.html
• http://secunia.com/advisories/35785
• http://secunia.com/advisories/35829
• http://secunia.com/advisories/35830
• http://secunia.com/advisories/35831
• http://secunia.com/advisories/35832
• http://secunia.com/advisories/35841
• http://secunia.com/advisories/35849
• http://secunia.com/advisories/35850
• http://secunia.com/advisories/35851
• http://secunia.com/advisories/35880
• http://secunia.com/advisories/36457
• http://secunia.com/advisories/37342
• http://secunia.com/advisories/40551
• http://security.gentoo.org/glsa/glsa-200907-12.xml
• http://slackware.com/security/viewer.php?l=slackware-security&y=2009&m=slackware-security.561471
• http://www.debian.org/security/2009/dsa-1833
• http://www.kb.cert.org/vuls/id/410676
• http://www.mandriva.com/security/advisories?name=MDVSA-2009:151
• http://www.osvdb.org/55819
• http://www.redhat.com/support/errata/RHSA-2009-1136.html
• http://www.redhat.com/support/errata/RHSA-2009-1154.html
• http://www.securityfocus.com/bid/35668
• http://www.securitytracker.com/id?1022548
• http://www.ubuntu.com/usn/usn-803-1
• http://www.vupen.com/english/advisories/2009/1891
• http://www.vupen.com/english/advisories/2010/1796
• https://bugzilla.redhat.com/show_bug.cgi?id=507717

Affected products (5)

• cpe:2.3:a:isc:dhcp:2.0:*:*:*:*:*:*:*
• cpe:2.3:a:isc:dhcp:3.0:*:*:*:*:*:*:*
• cpe:2.3:a:isc:dhcp:3.1:*:*:*:*:*:*:*
• cpe:2.3:a:isc:dhcp:4.0:*:*:*:*:*:*:*
• cpe:2.3:a:isc:dhcp:4.1.0:*:*:*:*:*:*:*

More vulnerabilities in Isc Dhcp

• CVE-2011-2749 — High (CVSS 7.8): The server in ISC DHCP 3.x and 4.x before 4.2.2, 3.1-ESV before 3.1-ESV-R3, and 4.1-ESV before 4.1-ESV-R3 allows remote…
• CVE-2011-2748 — High (CVSS 7.8): The server in ISC DHCP 3.x and 4.x before 4.2.2, 3.1-ESV before 3.1-ESV-R3, and 4.1-ESV before 4.1-ESV-R3 allows remote…
• CVE-2011-0413 — High (CVSS 7.8): The DHCPv6 server in ISC DHCP 4.0.x and 4.1.x before 4.1.2-P1, 4.0-ESV and 4.1-ESV before 4.1-ESV-R1, and 4.2.x before…
• CVE-2018-5732 — High (CVSS 7.5): Failure to properly bounds-check a buffer used for processing DHCP options allows a malicious server (or an entity…
• CVE-2018-5733 — High (CVSS 7.5): A malicious client which is allowed to send very large amounts of traffic (billions of packets) to a DHCP server can…
• CVE-2017-3144 — High (CVSS 7.5): A vulnerability stemming from failure to properly clean up closed OMAPI connections can lead to exhaustion of the pool…

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