CVE-2018-5740
A flaw in the "deny-answer-aliases" feature can cause an assertion failure in named
CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Description
"deny-answer-aliases" is a little-used feature intended to help recursive server operators protect end users against DNS rebinding attacks, a potential method of circumventing the security model used by client browsers. However, a defect in this feature makes it easy, when the feature is in use, to experience an assertion failure in name.c. Affects BIND 9.7.0->9.8.8, 9.9.0->9.9.13, 9.10.0->9.10.8, 9.11.0->9.11.4, 9.12.0->9.12.2, 9.13.0->9.13.2.
Official description from the CVE record, published by isc. Copyright © 1999-2026 The MITRE Corporation. See /security/cve/legal for the CVE license. View the record on cve.org
Key data
CVSS 3.0 High 7.5
CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Attack vector: Network
The vulnerable component can be reached over a network, possibly from the Internet.
Attack complexity: Low
No special conditions are needed. The attack can be repeated at will.
Privileges required: None
No account or privileges are needed.
User interaction: None
No action from any user is needed.
Scope: Unchanged
The impact stays within the vulnerable component.
Confidentiality impact: None
No effect on the secrecy of data.
Integrity impact: None
No effect on the trustworthiness of data.
Availability impact: High
Serious or total effect on availability.
| Metric | Value | What it means |
|---|---|---|
| Attack vector | Network | The vulnerable component can be reached over a network, possibly from the Internet. |
| Attack complexity | Low | No special conditions are needed. The attack can be repeated at will. |
| Privileges required | None | No account or privileges are needed. |
| User interaction | None | No action from any user is needed. |
| Scope | Unchanged | The impact stays within the vulnerable component. |
| Confidentiality impact | None | No effect on the secrecy of data. |
| Integrity impact | None | No effect on the trustworthiness of data. |
| Availability impact | High | Serious or total effect on availability. |
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EPSS
- Score
- 0.60236 (60.2% probability)
- Percentile
- 99.1%
- Scores of
- Nov 10, 2026
- Model
- v2026.06.15
Affected products
ISC BIND 9
- affected: BIND 9 9.7.0->9.8.8, 9.9.0->9.9.13, 9.10.0->9.10.8, 9.11.0->9.11.4, 9.12.0->9.12.2, 9.13.0->9.13.2
References
- 105055 (securityfocus.com)vdb-entry
- [debian-lts-announce] 20180830 [SECURITY] [DLA 1485-1] bind9 security update (lists.debian.org)mailing-list
- RHSA-2018:2570 (access.redhat.com)vendor-advisory
- RHSA-2018:2571 (access.redhat.com)vendor-advisory
- USN-3769-2 (usn.ubuntu.com)vendor-advisory
- 1041436 (securitytracker.com)vdb-entry
- security.netapp.com/advisory/ntap-20180926-0003
- kb.isc.org/docs/aa-01639
- USN-3769-1 (usn.ubuntu.com)vendor-advisory
- GLSA-201903-13 (security.gentoo.org)vendor-advisory
- openSUSE-SU-2019:1533 (lists.opensuse.org)vendor-advisory
- openSUSE-SU-2019:1532 (lists.opensuse.org)vendor-advisory
- support.hpe.com/hpsc/doc/public/display?docLocale=en_US&doc…
- [debian-lts-announce] 20211102 [SECURITY] [DLA 2807-1] bind9 security update (lists.debian.org)mailing-list
Timeline
- ID reserved
- Record published
- Record last updated
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Data from the CVE Program (MITRE), CISA KEV and FIRST EPSS. CVSS is owned by FIRST and used by permission. Not affiliated with or endorsed by MITRE, CISA or FIRST. Data as of Nov 10, 2026, 19:46 UTC. Sources and licenses