DNS-over-HTTPS implementation suffers from multiple issues under heavy query load
Clients using DNS-over-HTTPS (DoH) can exhaust a DNS resolver's CPU and/or memory by flooding it with crafted valid or invalid HTTP/2 traffic.
This issue affects BIND 9 versions 9.18.0 through 9.18.32, 9.20.0 through 9.20.4, 9.21.0 through 9.21.3, and 9.18.11-S1 through 9.18.32-S1.
Problem Types
| Type | CWE ID | Description |
|---|
| CWE | CWE-770 | CWE-770 Allocation of Resources Without Limits or Throttling |
Type: CWE
Description: CWE-770 Allocation of Resources Without Limits or Throttling
Metrics
| Version | Base score | Base severity | Vector |
|---|
| 3.1 | 7.5 | HIGH | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H |
Version: 3.1
Base score: 7.5
Base severity: HIGH
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Impacts
| CAPEC ID | Description |
|---|
| N/A | By flooding a target resolver with HTTP/2 traffic and exploiting this flaw, an attacker could overwhelm the server, causing high CPU and/or memory usage and preventing other clients from establishing DoH connections. This would significantly impair the resolver's performance and effectively deny legitimate clients access to the DNS resolution service. |
CAPEC ID: N/A
Description: By flooding a target resolver with HTTP/2 traffic and exploiting this flaw, an attacker could overwhelm the server, causing high CPU and/or memory usage and preventing other clients from establishing DoH connections. This would significantly impair the resolver's performance and effectively deny legitimate clients access to the DNS resolution service.