CVE-2009-3602

CVE-2009-3602 is a high-severity vulnerability in Nlnetlabs Unbound with a CVSS 2.0 base score of 7.5. 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-310.

Key facts

Description

Unbound before 1.3.4 does not properly verify signatures for NSEC3 records, which allows remote attackers to cause secure delegations to be downgraded via DNS spoofing or other DNS-related attacks in conjunction with crafted delegation responses.

Frequently asked questions

What is CVE-2009-3602?
Unbound before 1.3.4 does not properly verify signatures for NSEC3 records, which allows remote attackers to cause secure delegations to be downgraded via DNS spoofing or other DNS-related attacks in conjunction with crafted delegation responses.
How severe is CVE-2009-3602?
CVE-2009-3602 has a CVSS 2.0 base score of 7.5, rated high severity.
Is CVE-2009-3602 being actively exploited?
It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 3% (86th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2009-3602?
CVE-2009-3602 primarily affects Nlnetlabs Unbound. In total, 25 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2009-3602?
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-2009-3602 published?
CVE-2009-3602 was published on 2009-10-13 and last updated on 2026-06-16.

References

Affected products (25)

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