Bug 1762914 (CVE-2019-6475) - CVE-2019-6475 bind: A flaw in mirror zone validity checking can allow zone data to be spoofed
Summary: CVE-2019-6475 bind: A flaw in mirror zone validity checking can allow zone da...
Alias: CVE-2019-6475
Product: Security Response
Classification: Other
Component: vulnerability
Version: unspecified
Hardware: All
OS: Linux
Target Milestone: ---
Assignee: Red Hat Product Security
QA Contact:
Depends On: 1762915
Blocks: 1762961
TreeView+ depends on / blocked
Reported: 2019-10-17 19:28 UTC by kat
Modified: 2021-02-16 21:13 UTC (History)
10 users (show)

Fixed In Version: bind 9.15.5, bind 9.14.7
Doc Type: If docs needed, set a value
Doc Text:
Clone Of:
Last Closed: 2019-10-22 18:51:22 UTC

Attachments (Terms of Use)

Description kat 2019-10-17 19:28:01 UTC
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.


Comment 1 kat 2019-10-17 19:28:11 UTC
Created bind tracking bugs for this issue:

Affects: fedora-all [bug 1762915]

Comment 2 Tomas Hoger 2019-10-18 12:36:22 UTC
External References:


Comment 3 Tomas Hoger 2019-10-20 21:13:16 UTC
Upstream commit (9.15 branch):


Comment 4 Huzaifa S. Sidhpurwala 2019-10-22 05:03:15 UTC

This flaw did not affect the versions of bind shipped with Red Hat Enterprise Linux 6, 7 and 8.

Comment 5 Product Security DevOps Team 2019-10-22 18:51:22 UTC
This bug is now closed. Further updates for individual products will be reflected on the CVE page(s):


Comment 6 Michael Kaplan 2020-03-30 09:06:30 UTC
Please comment on RH and NVD CVSS difference.

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