CVE-2020-1700
Description
A flaw was found in the way the Ceph RGW Beast front-end handles unexpected disconnects. An authenticated attacker can abuse this flaw by making multiple disconnect attempts resulting in a permanent leak of a socket connection by radosgw. This flaw could lead to a denial of service condition by pile up of CLOSE_WAIT sockets, eventually leading to the exhaustion of available resources, preventing legitimate users from connecting to the system.
Statement
- Red Hat Ceph Storage 3 is not affected by this flaw, as beast is unsupported in the product.
- Red Hat Ceph Storage 4 is not affected by this flaw, as it is shipping patched version of ceph.
- Red Hat Openshift Container Storage 4.2 is affected by this flaw, as it is using the affected version of ceph.
- Red Hat OpenStack Platform 13 included some Ceph components at release for in order to support ppc64le. The version provided in the OpenStack repositories is outdated and customers are expected to be using versions provided in Ceph repositories now. Red Hat OpenStack Platform 13 operators should verify they are using Ceph repositories which are up to date and unaffected by this vulnerability.
- Red Hat Enterprise Linux 7 is not affected by this flaw, as it ships an old version of the code which does not include the vulnerable code.
- Red Hat Enterprise Linux 8 is not affected by this flaw, as only libcephfs-devel component is shipped and it does include the vulnerable code.
Mitigation
If Beast front end is in use, switch to CivetWeb to mitigate the issue. The following is an example of the /etc/ceph/ceph.conf file:
<snip>
...
[client.rgw.node1]
rgw frontends = civetweb
...
</snip>
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 | 6.5 | 6.5 | N/A |
| Attack Vector | Network | Network | 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:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
NVD: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
Understanding the Weakness (CWE)
Availability
Technical Impact: DoS: Crash, Exit, or Restart; DoS: Resource Consumption (CPU); DoS: Resource Consumption (Memory); DoS: Resource Consumption (Other)
If an attacker can trigger the allocation of the limited resources, but the number or size of the resources is not controlled, then the most common result is denial of service. This would prevent valid users from accessing the product, and it could potentially have an impact on the surrounding environment, i.e., the product may slow down, crash due to unhandled errors, or lock out legitimate users. For example, a memory exhaustion attack against an application could slow down the application as well as its host operating system.
Access Control,Other
Technical Impact: Bypass Protection Mechanism; Other
In some cases it may be possible to force the product to "fail open" in the event of resource exhaustion. The state of the product -- and possibly the security functionality - may then be compromised.
Acknowledgements
This issue was discovered by Or Friedman (Red Hat).
Frequently Asked Questions
Not sure what something means? Check out our Security Glossary.
Want to get errata notifications? Sign up here.
