Bug 2064512 (CVE-2021-25220) - CVE-2021-25220 bind: DNS forwarders - cache poisoning vulnerability
Summary: CVE-2021-25220 bind: DNS forwarders - cache poisoning vulnerability
Keywords:
Status: NEW
Alias: CVE-2021-25220
Product: Security Response
Classification: Other
Component: vulnerability
Version: unspecified
Hardware: All
OS: Linux
medium
medium
Target Milestone: ---
Assignee: Red Hat Product Security
QA Contact:
URL:
Whiteboard:
Depends On: 2072543 2072544 2072545 2072546 2072538 2072539 2072540 2072541
Blocks: 2064517
TreeView+ depends on / blocked
 
Reported: 2022-03-16 04:42 UTC by TEJ RATHI
Modified: 2022-08-06 01:28 UTC (History)
15 users (show)

Fixed In Version: bind 9.11.37, bind 9.16.27, bind 9.18.1
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Doc Text:
A cache poisoning vulnerability was found in BIND when using forwarders. Bogus NS records supplied by the forwarders may be cached and used by name if it needs to recurse for any reason. This issue causes it to obtain and pass on potentially incorrect answers. This flaw allows a remote, high privileged attacker to manipulate cache results with incorrect records, leading to queries made to the wrong servers, possibly resulting in false information received on the client's end.
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Description TEJ RATHI 2022-03-16 04:42:00 UTC 
When using forwarders, bogus NS records supplied by, or via, those forwarders may be cached and used by named if it needs to recurse for any reason, causing it to obtain and pass on potentially incorrect answers.

Some examples of configurations that will be vulnerable are:

*Resolvers using per zone or global forwarding with forward first (forward first is the default).
*Resolvers not using global forwarding, but with per-zone forwarding with either forward first (the default) or forward                only.
*Resolvers configured with global forwarding along with zone statements that disable forwarding for part of the DNS namespace.

Authoritative-only BIND 9 servers are not vulnerable to this flaw.
Comment 3 TEJ RATHI 2022-04-06 13:45:38 UTC 
Created bind tracking bugs for this issue:

Affects: fedora-34 [bug 2072538]
Affects: fedora-35 [bug 2072540]


Created dhcp tracking bugs for this issue:

Affects: fedora-34 [bug 2072539]
Affects: fedora-35 [bug 2072541]
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