CVE-2011-0997

CVE-2011-0997 is a high-severity vulnerability in Isc Dhcp with a CVSS 2.0 base score of 7.5. Its EPSS exploit-prediction score of 84% places it in the 100th percentile, indicating an elevated likelihood of exploitation. The underlying weakness is classified as CWE-20.

Key facts

• Severity: High (CVSS 2.0 base score 7.5)
• EPSS exploit prediction: 84% (100th percentile)
• Actively exploited: Not listed in CISA KEV
• Weakness: CWE-20
• Affected product: Isc Dhcp
• Published: 2011-04-08
• Last modified: 2026-06-16

Description

dhclient in ISC DHCP 3.0.x through 4.2.x before 4.2.1-P1, 3.1-ESV before 3.1-ESV-R1, and 4.1-ESV before 4.1-ESV-R2 allows remote attackers to execute arbitrary commands via shell metacharacters in a hostname obtained from a DHCP message, as demonstrated by a hostname that is provided to dhclient-script.

Frequently asked questions

What is CVE-2011-0997?

dhclient in ISC DHCP 3.0.x through 4.2.x before 4.2.1-P1, 3.1-ESV before 3.1-ESV-R1, and 4.1-ESV before 4.1-ESV-R2 allows remote attackers to execute arbitrary commands via shell metacharacters in a hostname obtained from a DHCP message, as demonstrated by a hostname that is provided to dhclient-script.

How severe is CVE-2011-0997?

CVE-2011-0997 has a CVSS 2.0 base score of 7.5, rated high severity.

Is CVE-2011-0997 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 84% (100th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2011-0997?

CVE-2011-0997 primarily affects Isc Dhcp. In total, 67 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2011-0997?

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

When was CVE-2011-0997 published?

CVE-2011-0997 was published on 2011-04-08 and last updated on 2026-06-16.

References

• http://kb.juniper.net/InfoCenter/index?page=content&id=JSA10761
• http://lists.fedoraproject.org/pipermail/package-announce/2011-April/057888.html
• http://lists.fedoraproject.org/pipermail/package-announce/2011-April/058279.html
• http://marc.info/?l=bugtraq&m=133226187115472&w=2
• http://secunia.com/advisories/44037
• http://secunia.com/advisories/44048
• http://secunia.com/advisories/44089
• http://secunia.com/advisories/44090
• http://secunia.com/advisories/44103
• http://secunia.com/advisories/44127
• http://secunia.com/advisories/44180
• http://security.gentoo.org/glsa/glsa-201301-06.xml
• http://securitytracker.com/id?1025300
• http://slackware.com/security/viewer.php?l=slackware-security&y=2011&m=slackware-security.593345
• http://www.debian.org/security/2011/dsa-2216
• http://www.debian.org/security/2011/dsa-2217
• http://www.kb.cert.org/vuls/id/107886
• http://www.mandriva.com/security/advisories?name=MDVSA-2011:073
• http://www.osvdb.org/71493
• http://www.redhat.com/support/errata/RHSA-2011-0428.html
• http://www.redhat.com/support/errata/RHSA-2011-0840.html
• http://www.securityfocus.com/bid/47176
• http://www.ubuntu.com/usn/USN-1108-1
• http://www.vupen.com/english/advisories/2011/0879
• http://www.vupen.com/english/advisories/2011/0886
• http://www.vupen.com/english/advisories/2011/0909
• http://www.vupen.com/english/advisories/2011/0915
• http://www.vupen.com/english/advisories/2011/0926
• http://www.vupen.com/english/advisories/2011/0965
• http://www.vupen.com/english/advisories/2011/1000

Affected products (67)

• cpe:2.3:a:isc:dhcp:3.0:*:*:*:*:*:*:*
• cpe:2.3:a:isc:dhcp:3.0.1:-:*:*:*:*:*:*
• cpe:2.3:a:isc:dhcp:3.0.1:rc1:*:*:*:*:*:*
• cpe:2.3:a:isc:dhcp:3.0.1:rc10:*:*:*:*:*:*
• cpe:2.3:a:isc:dhcp:3.0.1:rc11:*:*:*:*:*:*
• cpe:2.3:a:isc:dhcp:3.0.1:rc12:*:*:*:*:*:*
• cpe:2.3:a:isc:dhcp:3.0.1:rc13:*:*:*:*:*:*
• cpe:2.3:a:isc:dhcp:3.0.1:rc14:*:*:*:*:*:*
• cpe:2.3:a:isc:dhcp:3.0.1:rc2:*:*:*:*:*:*
• cpe:2.3:a:isc:dhcp:3.0.1:rc5:*:*:*:*:*:*
• cpe:2.3:a:isc:dhcp:3.0.1:rc6:*:*:*:*:*:*
• cpe:2.3:a:isc:dhcp:3.0.1:rc7:*:*:*:*:*:*
• cpe:2.3:a:isc:dhcp:3.0.1:rc8:*:*:*:*:*:*
• cpe:2.3:a:isc:dhcp:3.0.1:rc9:*:*:*:*:*:*
• cpe:2.3:a:isc:dhcp:3.0.2:-:*:*:*:*:*:*
• cpe:2.3:a:isc:dhcp:3.0.2:b1:*:*:*:*:*:*
• cpe:2.3:a:isc:dhcp:3.0.2:rc1:*:*:*:*:*:*
• cpe:2.3:a:isc:dhcp:3.0.2:rc2:*:*:*:*:*:*
• cpe:2.3:a:isc:dhcp:3.0.2:rc3:*:*:*:*:*:*
• cpe:2.3:a:isc:dhcp:3.0.3:-:*:*:*:*:*:*
• cpe:2.3:a:isc:dhcp:3.0.3:b1:*:*:*:*:*:*
• cpe:2.3:a:isc:dhcp:3.0.3:b2:*:*:*:*:*:*
• cpe:2.3:a:isc:dhcp:3.0.3:b3:*:*:*:*:*:*
• cpe:2.3:a:isc:dhcp:3.0.4:-:*:*:*:*:*:*
• cpe:2.3:a:isc:dhcp:3.0.4:b1:*:*:*:*:*:*
• cpe:2.3:a:isc:dhcp:3.0.4:b2:*:*:*:*:*:*
• cpe:2.3:a:isc:dhcp:3.0.4:b3:*:*:*:*:*:*
• cpe:2.3:a:isc:dhcp:3.0.4:rc1:*:*:*:*:*:*
• cpe:2.3:a:isc:dhcp:3.0.5:-:*:*:*:*:*:*
• cpe:2.3:a:isc:dhcp:3.0.5:rc1:*:*:*:*:*:*
• cpe:2.3:a:isc:dhcp:3.0.6:rc1:*:*:*:*:*:*
• cpe:2.3:a:isc:dhcp:3.1-esv:*:*:*:*:*:*:*
• cpe:2.3:a:isc:dhcp:3.1.0:-:*:*:*:*:*:*
• cpe:2.3:a:isc:dhcp:3.1.0:a1:*:*:*:*:*:*
• cpe:2.3:a:isc:dhcp:3.1.0:a2:*:*:*:*:*:*
• cpe:2.3:a:isc:dhcp:3.1.0:a3:*:*:*:*:*:*
• cpe:2.3:a:isc:dhcp:3.1.0:b1:*:*:*:*:*:*
• cpe:2.3:a:isc:dhcp:3.1.0:b2:*:*:*:*:*:*
• cpe:2.3:a:isc:dhcp:3.1.0:rc1:*:*:*:*:*:*
• cpe:2.3:a:isc:dhcp:3.1.1:rc1:*:*:*:*:*:*

More vulnerabilities in Isc Dhcp

• CVE-2009-0692 — Critical (CVSS 10.0): Stack-based buffer overflow in the script_write_params method in client/dhclient.c in ISC DHCP dhclient 4.1 before…
• 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…

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