CVE-2019-25039

Unspecified impact via response-IP size overflow

Published Apr 27, 2021 · Updated Aug 5, 2024

A disputed integer overflow in NLnet Labs Unbound before 1.9.5 has no established impact on remotely or locally running installations. In ub_packed_rrset_key(), unchecked multiplication and additions can wrap dsize before regional_alloc() uses the undersized result. NLnet Labs states that neither remote attackers nor local users can exploit a running installation, so no operational consequence is established.

CVSS severity9.8
Critical
EPSS probability2.04%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

A disputed integer overflow in NLnet Labs Unbound before 1.9.5 has no established impact on remotely or locally running installations. In ub_packed_rrset_key(), unchecked multiplication and additions can wrap dsize before regional_alloc() uses the undersized result. NLnet Labs states that neither remote attackers nor local users can exploit a running installation, so no operational consequence is established.

The record

CVE
CVE-2019-25039
Published
Apr 27, 2021
Updated
Aug 5, 2024
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-190
Attack vector
Unavailable
Privileges
Unavailable

Timeline

How it unfolded

  1. Apr 27, 2021CVE publishedPublication date reported by the CVE source.
  2. Aug 5, 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?

Affected buildAffected product and version details are unavailable.

What conditions does exploitation require?

Attack vectorUnavailable in this record.
Required privilegesUnavailable in this record.

What is affected?

Affected products and versions are unavailable in this record.

Published CVSS scores

9.8NIST NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
7.5NIST NVDAV:N/AC:L/Au:N/C:P/I:P/A:P

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.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

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

Weakness, pattern, technique

CWE-190Integer Overflow or Wraparound

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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