Unbound
CVE-2019-16866
HIGH
Vulnerability Assessment
| Weakness |
CWE
OWASP Top 10:2025
A10:2025 - Mishandling of Exceptional Conditions
ASVS 5.0
V16 - Security Logging and Error Handling Exception handling procedures
|
| Impact | CVSS score of 7.5 (HIGH). Attack characteristics: network attack vector, low complexity, no privileges required, no user interaction not required. |
| Exploit ScenarioDerived | This vulnerability can be exploited remotely over the network. Successful exploitation could compromise the high-severity affected system. |
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Alert meAnalysisAI
Unbound before 1.9.4 accesses uninitialized memory, which allows remote attackers to trigger a crash via a crafted NOTIFY query. Rated high severity (CVSS 7.5), this vulnerability is remotely exploitable, no authentication required, low attack complexity.
RemediationAI
A vendor patch is available. Apply the latest security update as soon as possible. Apply vendor patches when available. Implement network segmentation and monitoring as interim mitigations.
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Technical ContextAI · show details
This vulnerability is classified under CWE-755. Unbound before 1.9.4 accesses uninitialized memory, which allows remote attackers to trigger a crash via a crafted NOTIFY query. The source IP address of the query must match an access-control rule. Affected products include: Nlnetlabs Unbound, Canonical Ubuntu Linux. Version information: before 1.9.4.
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Severity by source
AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Primary rating from NVD · only source for this CVE.
CVSS VectorNVD
DescriptionNVD
Unbound before 1.9.4 accesses uninitialized memory, which allows remote attackers to trigger a crash via a crafted NOTIFY query. The source IP address of the query must match an access-control rule.
Threat Intelligence Overview
NVD
CVE.org
EPSS
GitHub
VulDB
How this decision was reached
The engine reads each signal below and applies a fixed list of rules from top to bottom. The first rule that matches sets the recommended action – like a statement, every line is shown.
What every action level means
SSVC AssessmentENISA
Priority Score
Attack Technique
Denial of Service attacks render applications or systems unavailable by overwhelming resources or triggering failure conditions.
Affected Products (CPE)NVD
Unbound 1.6.4 through 1.9.4 contain a vulnerability in the ipsec module that can cause shell code execution after receiv
A crafted DNSKEY whose owner name is a compression pointer into its own RDATA overflows the digest buffer in the DNSSEC
Use-after-free in the DNSSEC validator of NLnet Labs Unbound resolver versions 1.19.1 through 1.25.0 allows remote attac
Remote denial of service in NLnet Labs Unbound recursive DNS resolver (versions up to and including 1.25.0) allows an at
Heap overflow denial-of-service in NLnet Labs Unbound recursive DNS resolver versions 1.14.0 through 1.25.0 allows remot
Heap-based memory corruption in NLnet Labs Unbound up to and including 1.26.0 lets a remote, unauthenticated attacker wh
Remote denial of service in NLnet Labs Unbound 1.22.0 through 1.25.1 lets an unauthenticated client exhaust configured m
Remote denial-of-service in NLnet Labs Unbound 1.23.0 through 1.25.1 lets an attacker who controls a delegated DNS zone
Remote denial-of-service in NLnet Labs Unbound 1.9.0 through 1.25.1 allows an unauthenticated attacker to crash the recu
Heap buffer overflow in NLnet Labs Unbound 1.26.0 and earlier can be triggered when a resolver processing a large TCP-fr
Denial-of-service through algorithmic complexity attacks in NLnet Labs Unbound up to and including 1.26.0 can degrade or
Degradation of service in NLnet Labs Unbound up to and including 1.26.0 allows an unauthenticated remote attacker to mon
Exploit-DB