CVE-2018-5740
A flaw in the "deny-answer-aliases" feature can cause an assertion failure in named
- 7.5HighCVSS base score
- 60.2%Exploitation in 30 daysEPSS · top 0.9% of all CVEs
- NoKnown exploitednot in CISA's KEV catalog
- NonePublic exploitsnone known yet
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.
Timeline
ID reserved
By isc
- 12 months later
· 12 months later
Published
- 6 years later
· 6 years later
Record updated
Changes after publication (a new score, a public exploit, EPSS crossing 1, 10 or 50 %, leaving KEV) are kept since November 2026; earlier ones are not known.
Scores
| Scored by | CVSS | Score | Vector |
|---|---|---|---|
| iscCNA (assigner) | 3.0 | High7.5 | CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H |
| NVDNVD · Modified | 3.1 | High7.5 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H |
- EPSS (exploitation in 30 days)
- 60.2% · top 0.9% of all CVEs (9 Nov 2026)
The list uses the assigner's score when there is one, then CISA's, then NVD's: High 7.5.
Affected products
What to do
Solution: Most operators will not need to make any changes unless they are using the "deny-answer-aliases" feature (which is described in the BIND 9 Adminstrator Reference Manual section 6.2.) "deny-answer-aliases" is off by default; only configurations which explicitly enable it can be affected by this defect. If you are using "deny-answer-aliases", upgrade to the patched release most closely related to your current version of BIND. 9.9.13-P1 9.10.8-P1 9.11.4-P1 9.12.2-P1 BIND Supported Preview Edition is a special feature preview branch of BIND provided to eligible ISC support customers. 9.11.3-S3
Workaround: This vulnerability can be avoided by disabling the "deny-answer-aliases" feature if it is in use.
References
14
- 105055 (opens in a new tab)vdb-entryx_refsource_BIDx_transferred
- [debian-lts-announce] 20180830 [SECURITY] [DLA 1485-1] bind9 security update (opens in a new tab)mailing-listx_refsource_MLISTx_transferred
- RHSA-2018:2570 (opens in a new tab)vendor-advisoryx_refsource_REDHATx_transferred
- RHSA-2018:2571 (opens in a new tab)vendor-advisoryx_refsource_REDHATx_transferred
- USN-3769-2 (opens in a new tab)vendor-advisoryx_refsource_UBUNTUx_transferred
- 1041436 (opens in a new tab)vdb-entryx_refsource_SECTRACKx_transferred
- https://security.netapp.com/advisory/ntap-20180926-0003/ (opens in a new tab)x_refsource_CONFIRMx_transferred
- https://kb.isc.org/docs/aa-01639 (opens in a new tab)x_refsource_CONFIRMx_transferred
- USN-3769-1 (opens in a new tab)vendor-advisoryx_refsource_UBUNTUx_transferred
- GLSA-201903-13 (opens in a new tab)vendor-advisoryx_refsource_GENTOOx_transferred
- openSUSE-SU-2019:1533 (opens in a new tab)vendor-advisoryx_refsource_SUSEx_transferred
- openSUSE-SU-2019:1532 (opens in a new tab)vendor-advisoryx_refsource_SUSEx_transferred
- https://support.hpe.com/hpsc/doc/public/display?docLocale=en_US&docId=emr_na-hpesbux03927en_us (opens in a new tab)x_refsource_CONFIRMx_transferred
- [debian-lts-announce] 20211102 [SECURITY] [DLA 2807-1] bind9 security update (opens in a new tab)mailing-listx_refsource_MLISTx_transferred
Sources
The same CVE in the primary databases and aggregators, to check against.
- CVE.org record (opens in a new tab)
- CVE List JSON (GitHub) (opens in a new tab)
- NVD (opens in a new tab)
- FIRST EPSS (opens in a new tab)
- EUVD EUVD-2018-17509 (opens in a new tab)
- OSV.dev (opens in a new tab)
- GitHub Advisories (opens in a new tab)
- CIRCL Vulnerability-Lookup (opens in a new tab)
Badge for a README or a ticket
[](https://cveledger.app/cve/CVE-2018-5740)Record last updated .