# CVE-2018-5740: libirs160: "deny-answer-aliases" is a little-used feature intended to help recursive server operators protect end users against...

CVE-2018-5740 is fixed in 16 products on 1 platform, first by bind9 1:9.11.3+dfsg-1ubuntu1.2, released August 8, 2018. It is not reported as exploited. Patch Radar priority: Routine.

- Web page: https://patchblox.com/security/cve/CVE-2018-5740
- Priority: Routine
- CVSS: n/a (Medium)
- EPSS: 0.6024
- CISA KEV: not listed
- Exploited (vendor report): no
- Publicly disclosed: no
- Published: Aug 8, 2018

## 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.

## Where it's fixed

| Platform | Product | Fixed in | Fix | Released |
|---|---|---|---|---|
| Linux | bind9 Ubuntu 18.04.6 LTS (bionic) | 1:9.11.3+dfsg-1ubuntu1.2 | [bind9 1:9.11.3+dfsg-1ubuntu1.2](https://patchblox.com/security/data/fix/linux/ubuntu-bionic-bind9-1-9.11.3-dfsg-1ubuntu1.2.md) | Aug 8, 2018 |
| Linux | bind9-host Ubuntu 18.04.6 LTS (bionic) | 1:9.11.3+dfsg-1ubuntu1.2 | [bind9-host 1:9.11.3+dfsg-1ubuntu1.2](https://patchblox.com/security/data/fix/linux/ubuntu-bionic-bind9-host-1-9.11.3-dfsg-1ubuntu1.2.md) | Aug 8, 2018 |
| Linux | bind9utils Ubuntu 18.04.6 LTS (bionic) | 1:9.11.3+dfsg-1ubuntu1.2 | [bind9utils 1:9.11.3+dfsg-1ubuntu1.2](https://patchblox.com/security/data/fix/linux/ubuntu-bionic-bind9utils-1-9.11.3-dfsg-1ubuntu1.2.md) | Aug 8, 2018 |
| Linux | dnsutils Ubuntu 18.04.6 LTS (bionic) | 1:9.11.3+dfsg-1ubuntu1.2 | [dnsutils 1:9.11.3+dfsg-1ubuntu1.2](https://patchblox.com/security/data/fix/linux/ubuntu-bionic-dnsutils-1-9.11.3-dfsg-1ubuntu1.2.md) | Aug 8, 2018 |
| Linux | libbind9-160 Ubuntu 18.04.6 LTS (bionic) | 1:9.11.3+dfsg-1ubuntu1.2 | [libbind9-160 1:9.11.3+dfsg-1ubuntu1.2](https://patchblox.com/security/data/fix/linux/ubuntu-bionic-libbind9-160-1-9.11.3-dfsg-1ubuntu1.2.md) | Aug 8, 2018 |
| Linux | libdns-export1100 Ubuntu 18.04.6 LTS (bionic) | 1:9.11.3+dfsg-1ubuntu1.2 | [libdns-export1100 1:9.11.3+dfsg-1ubuntu1.2](https://patchblox.com/security/data/fix/linux/ubuntu-bionic-libdns-export1100-1-9.11.3-dfsg-1ubuntu1.2.md) | Aug 8, 2018 |
| Linux | libdns1100 Ubuntu 18.04.6 LTS (bionic) | 1:9.11.3+dfsg-1ubuntu1.2 | [libdns1100 1:9.11.3+dfsg-1ubuntu1.2](https://patchblox.com/security/data/fix/linux/ubuntu-bionic-libdns1100-1-9.11.3-dfsg-1ubuntu1.2.md) | Aug 8, 2018 |
| Linux | libirs-export160 Ubuntu 18.04.6 LTS (bionic) | 1:9.11.3+dfsg-1ubuntu1.2 | [libirs-export160 1:9.11.3+dfsg-1ubuntu1.2](https://patchblox.com/security/data/fix/linux/ubuntu-bionic-libirs-export160-1-9.11.3-dfsg-1ubuntu1.2.md) | Aug 8, 2018 |
| Linux | libirs160 Ubuntu 18.04.6 LTS (bionic) | 1:9.11.3+dfsg-1ubuntu1.2 | [libirs160 1:9.11.3+dfsg-1ubuntu1.2](https://patchblox.com/security/data/fix/linux/ubuntu-bionic-libirs160-1-9.11.3-dfsg-1ubuntu1.2.md) | Aug 8, 2018 |
| Linux | libisc-export169 Ubuntu 18.04.6 LTS (bionic) | 1:9.11.3+dfsg-1ubuntu1.2 | [libisc-export169 1:9.11.3+dfsg-1ubuntu1.2](https://patchblox.com/security/data/fix/linux/ubuntu-bionic-libisc-export169-1-9.11.3-dfsg-1ubuntu1.2.md) | Aug 8, 2018 |
| Linux | libisc169 Ubuntu 18.04.6 LTS (bionic) | 1:9.11.3+dfsg-1ubuntu1.2 | [libisc169 1:9.11.3+dfsg-1ubuntu1.2](https://patchblox.com/security/data/fix/linux/ubuntu-bionic-libisc169-1-9.11.3-dfsg-1ubuntu1.2.md) | Aug 8, 2018 |
| Linux | libisccc-export160 Ubuntu 18.04.6 LTS (bionic) | 1:9.11.3+dfsg-1ubuntu1.2 | [libisccc-export160 1:9.11.3+dfsg-1ubuntu1.2](https://patchblox.com/security/data/fix/linux/ubuntu-bionic-libisccc-export160-1-9.11.3-dfsg-1ubuntu1.2.md) | Aug 8, 2018 |
| Linux | libisccc160 Ubuntu 18.04.6 LTS (bionic) | 1:9.11.3+dfsg-1ubuntu1.2 | [libisccc160 1:9.11.3+dfsg-1ubuntu1.2](https://patchblox.com/security/data/fix/linux/ubuntu-bionic-libisccc160-1-9.11.3-dfsg-1ubuntu1.2.md) | Aug 8, 2018 |
| Linux | libisccfg-export160 Ubuntu 18.04.6 LTS (bionic) | 1:9.11.3+dfsg-1ubuntu1.2 | [libisccfg-export160 1:9.11.3+dfsg-1ubuntu1.2](https://patchblox.com/security/data/fix/linux/ubuntu-bionic-libisccfg-export160-1-9.11.3-dfsg-1ubuntu1.2.md) | Aug 8, 2018 |
| Linux | libisccfg160 Ubuntu 18.04.6 LTS (bionic) | 1:9.11.3+dfsg-1ubuntu1.2 | [libisccfg160 1:9.11.3+dfsg-1ubuntu1.2](https://patchblox.com/security/data/fix/linux/ubuntu-bionic-libisccfg160-1-9.11.3-dfsg-1ubuntu1.2.md) | Aug 8, 2018 |
| Linux | liblwres160 Ubuntu 18.04.6 LTS (bionic) | 1:9.11.3+dfsg-1ubuntu1.2 | [liblwres160 1:9.11.3+dfsg-1ubuntu1.2](https://patchblox.com/security/data/fix/linux/ubuntu-bionic-liblwres160-1-9.11.3-dfsg-1ubuntu1.2.md) | Aug 8, 2018 |

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Data as of 2026-11-07T12:40:37Z UTC. Source: Patchblox Patch Radar (https://patchblox.com/security/patch-radar). Patchblox finds out-of-date software on Windows, macOS and Linux and updates it through release rings: https://patchblox.com/demo