CVE-2022-0396
Description
A flaw was found in Bind that incorrectly handles certain crafted TCP streams. The vulnerability allows TCP connection slots to be consumed for an indefinite time frame via a specifically crafted TCP stream sent from a client. This flaw allows a remote attacker to send specially crafted TCP streams with 'keep-response-order' enabled that could cause connections to BIND to remain in CLOSE_WAIT status for an indefinite period, even after the client has terminated the connection. This issue results in BIND consuming resources, leading to a denial of service.
Statement
This issue can only be triggered on BIND servers that have the keep-response-order enabled, which is not the default configuration. The keep-response-order option is an ACL block; any hosts which are specified within it will be able to trigger this issue on affected versions.
Only the BIND9.16 package in RHEL-8 and the BIND package in RHEL-9 are affected, because of the presence of vulnerable code in our codebase.
Mitigation
To mitigate this issue in all affected versions of BIND, use the default setting of :
keep-response-order { none; }
Common Vulnerability Scoring System (CVSS) Score Details
Info alert:Important note
CVSS scores for open source components depend on vendor-specific factors (e.g. version or build chain). Therefore, Red Hat's score and impact rating can be different from NVD and other vendors. Red Hat remains the authoritative CVE Naming Authority (CNA) source for its products and services (see Red Hat classifications).
CVSS v3 Score Breakdown
| Red Hat | NVD | cve.org | |
|---|---|---|---|
| Base Score | 5.3 | 5.3 | N/A |
| Attack Vector | Network | Network | N/A |
| Attack Complexity | Low | Low | N/A |
| Privileges Required | None | None | N/A |
| User Interaction | None | None | N/A |
| Scope | Unchanged | Unchanged | N/A |
| Confidentiality | None | None | N/A |
| Integrity Impact | None | None | N/A |
| Availability Impact | Low | Low | N/A |
Vector
Red Hat: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L
NVD: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L
Understanding the Weakness (CWE)
Availability
Technical Impact: DoS: Resource Consumption (Other); DoS: Resource Consumption (Memory); DoS: Resource Consumption (CPU)
An attacker that can influence the allocation of resources that are not properly released could deplete the available resource pool and prevent all other processes from accessing the same type of resource. Frequently-affected resources include memory, CPU, disk space, power or battery, etc.
Frequently Asked Questions
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