CVE-2019-20096
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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.
Additional information
- Bugzilla 1791959: kernel: memory leak in __feat_register_sp() in net/dccp/feat.c
- CWE-772: Missing Release of Resource after Effective Lifetime
- FAQ: Frequently asked questions about CVE-2019-20096
Common Vulnerability Scoring System (CVSS) Score Details
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.
| Red Hat | NVD | |
|---|---|---|
CVSS v3 Base Score | 5.5 | 5.5 |
Attack Vector | Local | Local |
Attack Complexity | Low | Low |
Privileges Required | Low | Low |
User Interaction | None | None |
Scope | Unchanged | Unchanged |
Confidentiality Impact | None | None |
Integrity Impact | None | None |
Availability Impact | High | High |
CVSS v3 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
Frequently Asked Questions
Why is Red Hat's CVSS v3 score or Impact different from other vendors?
My product is listed as "Under investigation" or "Affected", when will Red Hat release a fix for this vulnerability?
What can I do if my product is listed as "Will not fix"?
What can I do if my product is listed as "Fix deferred"?
What is a mitigation?
I have a Red Hat product but it is not in the above list, is it affected?
Why is my security scanner reporting my product as vulnerable to this vulnerability even though my product version is fixed or not affected?
My product is listed as "Out of Support Scope". What does this mean?
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