CVE-2024-8508Network attack vector

Service interruption via unbounded name compression

Published Oct 3, 2024 · Updated Nov 14, 2024

Denial of service in NLnet Labs Unbound 1.21.0 and earlier allows remote attackers to interrupt DNS service via large RRsets. The downstream reply path performs an unbounded number of name-compression calculations while constructing a packet, monopolizing a CPU until the packet is complete. Exploitation requires a queried attacker-controlled zone to return specially crafted, very large RRsets; orchestrated requests degrade resolution and can deny service.

CVSS severity5.3
Medium
EPSS probability0.80%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Denial of service in NLnet Labs Unbound 1.21.0 and earlier allows remote attackers to interrupt DNS service via large RRsets. The downstream reply path performs an unbounded number of name-compression calculations while constructing a packet, monopolizing a CPU until the packet is complete. Exploitation requires a queried attacker-controlled zone to return specially crafted, very large RRsets; orchestrated requests degrade resolution and can deny service.

The record

CVE
CVE-2024-8508
Published
Oct 3, 2024
Updated
Nov 14, 2024
Vendor
NLnet Labs
Product
Unbound
Classifications
CWE-606, T1499
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Oct 3, 2024CVE publishedPublication date reported by the CVE source.
  2. Nov 14, 2024Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=0 <=1.21.0

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

NLnet Labs · Unboundversion=0 <=1.21.0

Published CVSS scores

5.3NLnet LabsCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

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No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-606Unchecked Input for Loop Condition
T1499Endpoint Denial of Service

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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