CVSS3
Attack Vector
NETWORK
Attack Complexity
LOW
Privileges Required
NONE
User Interaction
NONE
Scope
UNCHANGED
Confidentiality Impact
NONE
Integrity Impact
NONE
Availability Impact
HIGH
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
AI Score
Confidence
High
EPSS
Percentile
40.3%
This issue can affect BIND 9 resolvers with stale-answer-enable yes;
that also make use of the option stale-answer-client-timeout
, configured with a value greater than zero.
If the resolver receives many queries that require recursion, there will be a corresponding increase in the number of clients that are waiting for recursion to complete. If there are sufficient clients already waiting when a new client query is received so that it is necessary to SERVFAIL the longest waiting client (see BIND 9 ARM recursive-clients
limit and soft quota), then it is possible for a race to occur between providing a stale answer to this older client and sending an early timeout SERVFAIL, which may cause an assertion failure.
This issue affects BIND 9 versions 9.16.12 through 9.16.36, 9.18.0 through 9.18.10, 9.19.0 through 9.19.8, and 9.16.12-S1 through 9.16.36-S1.
Vendor | Product | Version | CPE |
---|---|---|---|
isc | bind | * | cpe:2.3:a:isc:bind:*:*:*:*:-:*:*:* |
isc | bind | 9.16.12 | cpe:2.3:a:isc:bind:9.16.12:s1:*:*:supported_preview:*:*:* |
isc | bind | 9.16.13 | cpe:2.3:a:isc:bind:9.16.13:s1:*:*:supported_preview:*:*:* |
isc | bind | 9.16.14 | cpe:2.3:a:isc:bind:9.16.14:s1:*:*:supported_preview:*:*:* |
isc | bind | 9.16.21 | cpe:2.3:a:isc:bind:9.16.21:s1:*:*:supported_preview:*:*:* |
isc | bind | 9.16.32 | cpe:2.3:a:isc:bind:9.16.32:s1:*:*:supported_preview:*:*:* |
isc | bind | 9.16.36 | cpe:2.3:a:isc:bind:9.16.36:s1:*:*:supported_preview:*:*:* |
[
{
"vendor": "ISC",
"product": "BIND 9",
"versions": [
{
"version": "9.16.12",
"lessThanOrEqual": "9.16.36",
"status": "affected",
"versionType": "custom"
},
{
"version": "9.18.0",
"lessThanOrEqual": "9.18.10",
"status": "affected",
"versionType": "custom"
},
{
"version": "9.19.0",
"lessThanOrEqual": "9.19.8",
"status": "affected",
"versionType": "custom"
},
{
"version": "9.16.12-S1",
"lessThanOrEqual": "9.16.36-S1",
"status": "affected",
"versionType": "custom"
}
],
"defaultStatus": "unaffected"
}
]