If a BIND resolver has cached a tree of SVCB/HTTPS AliasMode records, and is then queried for the root of that tree, the resolver will spend disproportionate CPU time constructing the response.
This issue affects BIND 9 versions 9.18.0 through 9.18.50, 9.20.0 through 9.20.27, 9.21.0 through 9.21.25, 9.18.11-S1 through 9.18.50-S1, and 9.20.9-S1 through 9.20.27-S1.
Attack Parameters
Attack Vector
Network
Can be exploited remotely
Attack Complexity
Low
Easy to exploit
Privileges Required
None
No privileges needed
User Interaction
None
No user interaction needed
Impact Assessment
Confidentiality
None
No data leak
Integrity
None
No data modification
Availability
High
Complete denial of service
CVSS Vector v3.1
Weakness Type (CWE)
Vulnerable Products 5
| Configuration | From (including) | Up to (excluding) |
|---|---|---|
|
Isc Bind
cpe:2.3:a:isc:bind:*:*:*:*:*:*:*:*
|
9.18.0
|
<= 9.18.50
|
|
Isc Bind
cpe:2.3:a:isc:bind:*:*:*:*:*:*:*:*
|
9.20.0
|
<= 9.20.27
|
|
Isc Bind
cpe:2.3:a:isc:bind:*:*:*:*:*:*:*:*
|
9.21.0
|
<= 9.21.25
|
|
Isc Bind
cpe:2.3:a:isc:bind:*:*:*:*:*:*:*:*
|
9.18.11-S1
|
<= 9.18.50-S1
|
|
Isc Bind
cpe:2.3:a:isc:bind:*:*:*:*:*:*:*:*
|
9.20.9-S1
|
<= 9.20.27-S1
|