CVE-2019-6475
A flaw in mirror zone validity checking can allow zone data to be spoofed
- Published
- Updated
- Reserved
- Assigned by
- isc
Description
Mirror zones are a BIND feature allowing recursive servers to pre-cache zone data provided by other servers. A mirror zone is similar to a zone of type secondary, except that its data is subject to DNSSEC validation before being used in answers, as if it had been looked up via traditional recursion, and when mirror zone data cannot be validated, BIND falls back to using traditional recursion instead of the mirror zone. However, an error in the validity checks for the incoming zone data can allow an on-path attacker to replace zone data that was validated with a configured trust anchor with forged data of the attacker's choosing. The mirror zone feature is most often used to serve a local copy of the root zone. If an attacker was able to insert themselves into the network path between a recursive server using a mirror zone and a root name server, this vulnerability could then be used to cause the recursive server to accept a copy of falsified root zone data. This affects BIND versions 9.14.0 up to 9.14.6, and 9.15.0 up to 9.15.4.
Scores
| Scored by | CVSS | Score | Vector |
|---|---|---|---|
| iscCNA (assigner) | 3.1 | Medium5.9 | CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:H/A:N |
| NVDNVD · Modified | 3.1 | High7.5 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N |
- EPSS (exploitation in 30 days)
- 1.4% · top 28% of all CVEs (5 Nov 2026)
The list uses the assigner's score when there is one, then CISA's, then NVD's: Medium 5.9.
Weakness
- An on-path attacker who manages to successfully exploit this vulnerability can replace the mirrored zone (usually the root) with data of their own choosing, effectively bypassing DNSSEC protection.
- CWE-345 (opens in a new tab)All about CWE-345 and its CVEs
Affected products
What to do
Solution: Upgrade to the patched release most closely related to your current version of BIND: + BIND 9.14.7 + BIND 9.15.5
Workaround: The vulnerability can be avoided by not using mirror zones.
References (3)
- https://kb.isc.org/docs/cve-2019-6475 (opens in a new tab)x_refsource_CONFIRMx_transferred
- https://security.netapp.com/advisory/ntap-20191024-0004/ (opens in a new tab)x_refsource_CONFIRMx_transferred
- https://support.f5.com/csp/article/K42238532?utm_source=f5support&%3Butm_medium=RSS (opens in a new tab)x_refsource_CONFIRMx_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)
- 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://trackcve.app/cve/CVE-2019-6475)Record last updated .