CVE-2019-20096
Description
A flaw was found in the Linux kernel’s implementation of the Datagram Congestion Control Protocol (DCCP). A local attacker with access to the system can create DCCP sockets to cause a memory leak and repeat this operation to exhaust all memory and panic the system.
Mitigation
As the DCCP module will be auto-loaded when required, its use can be disabled. Red Hat Enterprise Linux 7.5 (and later) and 8.0 (and later) already have this disabled, but for any other version, the system can prevent the module from loading with the following instructions :
# echo "install dccp /bin/true" >> /etc/modprobe.d/disable-dccp.conf
The system will need to be restarted if the DCCP modules are loaded. In most circumstances, the DCCP kernel modules will be unable to be unloaded while any network interfaces are active and the protocol is in use.
If you need further assistance, see KCS article https://access.redhat.com/solutions/41278 or contact Red Hat Global Support Services.
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).
The following CVSS metrics and score provided are preliminary and subject to review.
CVSS v3 Score Breakdown
| Red Hat | NVD | cve.org | |
|---|---|---|---|
| Base Score | 5.5 | 5.5 | N/A |
| Attack Vector | Local | Local | N/A |
| Attack Complexity | Low | Low | N/A |
| Privileges Required | Low | Low | 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 | High | High | N/A |
Vector
Red Hat: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
NVD: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
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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