How severe is CVE-2009-4008?

CVE-2009-4008 has a CVSS 2.0 base score of 5.0, rated medium severity.

Is CVE-2009-4008 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 3% (84th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2009-4008?

CVE-2009-4008 primarily affects Nlnetlabs Unbound. In total, 30 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2009-4008?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.

When was CVE-2009-4008 published?

CVE-2009-4008 was published on 2011-06-02 and last updated on 2026-06-16.

CVE-2009-4008

CVE-2009-4008 is a medium-severity vulnerability in Nlnetlabs Unbound with a CVSS 2.0 base score of 5.0. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-399.

Key facts

Severity: Medium (CVSS 2.0 base score 5.0)
EPSS exploit prediction: 3% (84th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-399
Affected product: Nlnetlabs Unbound
Published: 2011-06-02
Last modified: 2026-06-16

Description

Unbound before 1.4.4 does not send responses for signed zones after mishandling an unspecified query, which allows remote attackers to cause a denial of service (DNSSEC outage) via a crafted query.

Frequently asked questions

What is CVE-2009-4008?: Unbound before 1.4.4 does not send responses for signed zones after mishandling an unspecified query, which allows remote attackers to cause a denial of service (DNSSEC outage) via a crafted query.
How severe is CVE-2009-4008?: CVE-2009-4008 has a CVSS 2.0 base score of 5.0, rated medium severity.
Is CVE-2009-4008 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 3% (84th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2009-4008?: CVE-2009-4008 primarily affects Nlnetlabs Unbound. In total, 30 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2009-4008?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2009-4008 published?: CVE-2009-4008 was published on 2011-06-02 and last updated on 2026-06-16.

References

Affected products (30)

cpe:2.3:a:nlnetlabs:unbound:*:*:*:*:*:*:*:*
cpe:2.3:a:nlnetlabs:unbound:0.0:*:*:*:*:*:*:*
cpe:2.3:a:nlnetlabs:unbound:0.1:*:*:*:*:*:*:*
cpe:2.3:a:nlnetlabs:unbound:0.2:*:*:*:*:*:*:*
cpe:2.3:a:nlnetlabs:unbound:0.3:*:*:*:*:*:*:*
cpe:2.3:a:nlnetlabs:unbound:0.4:*:*:*:*:*:*:*
cpe:2.3:a:nlnetlabs:unbound:0.5:*:*:*:*:*:*:*
cpe:2.3:a:nlnetlabs:unbound:0.6:*:*:*:*:*:*:*
cpe:2.3:a:nlnetlabs:unbound:0.7:*:*:*:*:*:*:*
cpe:2.3:a:nlnetlabs:unbound:0.7.1:*:*:*:*:*:*:*
cpe:2.3:a:nlnetlabs:unbound:0.7.2:*:*:*:*:*:*:*
cpe:2.3:a:nlnetlabs:unbound:0.8:*:*:*:*:*:*:*
cpe:2.3:a:nlnetlabs:unbound:0.09:*:*:*:*:*:*:*
cpe:2.3:a:nlnetlabs:unbound:0.10:*:*:*:*:*:*:*
cpe:2.3:a:nlnetlabs:unbound:0.11:*:*:*:*:*:*:*
cpe:2.3:a:nlnetlabs:unbound:1.0.0:*:*:*:*:*:*:*
cpe:2.3:a:nlnetlabs:unbound:1.0.1:*:*:*:*:*:*:*
cpe:2.3:a:nlnetlabs:unbound:1.0.2:*:*:*:*:*:*:*
cpe:2.3:a:nlnetlabs:unbound:1.1.0:*:*:*:*:*:*:*
cpe:2.3:a:nlnetlabs:unbound:1.1.1:*:*:*:*:*:*:*
cpe:2.3:a:nlnetlabs:unbound:1.2.0:*:*:*:*:*:*:*
cpe:2.3:a:nlnetlabs:unbound:1.2.1:*:*:*:*:*:*:*
cpe:2.3:a:nlnetlabs:unbound:1.3.0:*:*:*:*:*:*:*
cpe:2.3:a:nlnetlabs:unbound:1.3.1:*:*:*:*:*:*:*
cpe:2.3:a:nlnetlabs:unbound:1.3.2:*:*:*:*:*:*:*
cpe:2.3:a:nlnetlabs:unbound:1.3.3:*:*:*:*:*:*:*
cpe:2.3:a:nlnetlabs:unbound:1.3.4:*:*:*:*:*:*:*
cpe:2.3:a:nlnetlabs:unbound:1.4.0:*:*:*:*:*:*:*
cpe:2.3:a:nlnetlabs:unbound:1.4.1:*:*:*:*:*:*:*
cpe:2.3:a:nlnetlabs:unbound:1.4.2:*:*:*:*:*:*:*

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Other CWE-399 (Resource Management Errors) vulnerabilities

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CVE-2015-0339 — Critical (CVSS 10.0): Adobe Flash Player before 13.0.0.277 and 14.x through 17.x before 17.0.0.134 on Windows and OS X and before…
CVE-2015-0335 — Critical (CVSS 10.0): Adobe Flash Player before 13.0.0.277 and 14.x through 17.x before 17.0.0.134 on Windows and OS X and before…
CVE-2015-0333 — Critical (CVSS 10.0): Adobe Flash Player before 13.0.0.277 and 14.x through 17.x before 17.0.0.134 on Windows and OS X and before…
CVE-2014-4121 — Critical (CVSS 10.0): Microsoft .NET Framework 2.0 SP2, 3.5, 3.5.1, 4, 4.5, 4.5.1, and 4.5.2 does not properly parse internationalized…
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