VDB-161810 · CVE-2020-25601 · GCVE-0-2020-25601

Xen up to 4.14.x FIFO Event Channel evtchn_reset/evtchn_destroy denial of service

CVSS Meta Temp Score CVSS is a standardized scoring system to determine possibilities of attacks. The Temp Score considers temporal factors like disclosure, exploit and countermeasures. The unique Meta Score calculates the average score of different sources to provide a normalized scoring system.	Current Exploit Price (≈) Our analysts are monitoring exploit markets and are in contact with vulnerability brokers. The range indicates the observed or calculated exploit price to be seen on exploit markets. A good indicator to understand the monetary effort required for and the popularity of an attack.	CTI Interest Score Our Cyber Threat Intelligence team is monitoring different web sites, mailing lists, exploit markets and social media networks. The CTI Interest Score identifies the interest of attackers and the security community for this specific vulnerability in real-time. A high score indicates an elevated risk to be targeted for this vulnerability.
3.2	$0-$5k	0.00

Summaryinfo

A vulnerability described as problematic has been identified in Xen up to 4.14.x. Affected by this vulnerability is the function evtchn_reset/evtchn_destroy of the component FIFO Event Channel Handler. Such manipulation leads to denial of service. This vulnerability is referenced as CVE-2020-25601. No exploit is available. Upgrading the affected component is recommended.

Detailsinfo

A vulnerability was found in Xen up to 4.14.x (Virtualization Software). It has been rated as problematic. Affected by this issue is the function evtchn_reset/evtchn_destroy of the component FIFO Event Channel Handler. The manipulation with an unknown input leads to a denial of service vulnerability. Using CWE to declare the problem leads to CWE-404. The product does not release or incorrectly releases a resource before it is made available for re-use. Impacted is availability. CVE summarizes:

An issue was discovered in Xen through 4.14.x. There is a lack of preemption in evtchn_reset() / evtchn_destroy(). In particular, the FIFO event channel model allows guests to have a large number of event channels active at a time. Closing all of these (when resetting all event channels or when cleaning up after the guest) may take extended periods of time. So far, there was no arrangement for preemption at suitable intervals, allowing a CPU to spend an almost unbounded amount of time in the processing of these operations. Malicious or buggy guest kernels can mount a Denial of Service (DoS) attack affecting the entire system. All Xen versions are vulnerable in principle. Whether versions 4.3 and older are vulnerable depends on underlying hardware characteristics.

The weakness was published 09/23/2020. This vulnerability is handled as CVE-2020-25601 since 09/16/2020. Technical details are known, but there is no available exploit.

Upgrading eliminates this vulnerability.

Similar entries are available at VDB-161813, VDB-161812, VDB-161811 and VDB-161809. If you want to get best quality of vulnerability data, you may have to visit VulDB.

Affected

Xen
Citrix Hypervisor up to 8.2 LTSR

Productinfo

Type

Virtualization Software

Name

Version

License

open-source

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔍
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 3.3
VulDB Meta Temp Score: 3.2

VulDB Base Score: 3.3
VulDB Temp Score: 3.2
VulDB Vector: 🔍
VulDB Reliability: 🔍

CVSSv2info

AV	AC	Au	C	I	A
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💳	💳	💳	💳	💳	💳
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Vector	Complexity	Authentication	Confidentiality	Integrity	Availability
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VulDB Base Score: 🔍
VulDB Temp Score: 🔍
VulDB Reliability: 🔍

Exploitinginfo

Class: Denial of service
CWE: CWE-404
CAPEC: 🔍
ATT&CK: 🔍

Physical: Partially
Local: Yes
Remote: No

Availability: 🔍
Status: Not defined

EPSS Score: 🔍
EPSS Percentile: 🔍

Price Prediction: 🔍
Current Price Estimation: 🔍

0-Day	Unlock	Unlock	Unlock	Unlock
Today	Unlock	Unlock	Unlock	Unlock

Threat Intelligenceinfo

Interest: 🔍
Active Actors: 🔍
Active APT Groups: 🔍

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔍

Timelineinfo

09/16/2020 🔍
09/23/2020 +7 days 🔍
09/24/2020 +1 days 🔍
09/30/2020 +6 days 🔍

Sourcesinfo

Status: Not defined

CVE: CVE-2020-25601 (🔍)
GCVE (CVE): GCVE-0-2020-25601
GCVE (VulDB): GCVE-100-161810
See also: 🔍

Entryinfo

Created: 09/24/2020 07:46
Updated: 09/30/2020 21:43
Changes: 09/24/2020 07:46 (37), 09/30/2020 21:43 (4)
Complete: 🔍
Cache ID: 216::103

If you want to get best quality of vulnerability data, you may have to visit VulDB.