Xen up to 4.14.x Timer Migration race condition

CVSS Meta Temp Score
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CTI Interest Score
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4.5$0-$5k0.00

Summaryinfo

A vulnerability, which was classified as critical, has been found in Xen up to 4.14.x. This vulnerability affects unknown code of the component Timer Migration Handler. The manipulation leads to race condition. This vulnerability is listed as CVE-2020-25604. The attack must be carried out locally. There is no available exploit. It is advisable to upgrade the affected component.

Detailsinfo

A vulnerability, which was classified as critical, has been found in Xen up to 4.14.x (Virtualization Software). This issue affects an unknown functionality of the component Timer Migration Handler. The manipulation with an unknown input leads to a race condition vulnerability. Using CWE to declare the problem leads to CWE-362. The product contains a code sequence that can run concurrently with other code, and the code sequence requires temporary, exclusive access to a shared resource, but a timing window exists in which the shared resource can be modified by another code sequence that is operating concurrently. Impacted is availability. The summary by CVE is:

An issue was discovered in Xen through 4.14.x. There is a race condition when migrating timers between x86 HVM vCPUs. When migrating timers of x86 HVM guests between its vCPUs, the locking model used allows for a second vCPU of the same guest (also operating on the timers) to release a lock that it didn't acquire. The most likely effect of the issue is a hang or crash of the hypervisor, i.e., a Denial of Service (DoS). All versions of Xen are affected. Only x86 systems are vulnerable. Arm systems are not vulnerable. Only x86 HVM guests can leverage the vulnerability. x86 PV and PVH cannot leverage the vulnerability. Only guests with more than one vCPU can exploit the vulnerability.

The weakness was presented 09/23/2020. The identification of this vulnerability is CVE-2020-25604 since 09/16/2020. An attack has to be approached locally. No form of authentication is needed for a successful exploitation. Neither technical details nor an exploit are publicly available.

Upgrading eliminates this vulnerability.

See VDB-161812, VDB-161811, VDB-161810 and VDB-161809 for similar entries. If you want to get the best quality for vulnerability data then you always have to consider VulDB.

Affected

  • Xen
  • Citrix Hypervisor up to 8.2 LTSR

Productinfo

Type

Name

Version

License

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔍
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 4.7
VulDB Meta Temp Score: 4.6

VulDB Base Score: 4.7
VulDB Temp Score: 4.5
VulDB Vector: 🔍
VulDB Reliability: 🔍

NVD Base Score: 4.7
NVD Vector: 🔍

CVSSv2info

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VulDB Base Score: 🔍
VulDB Temp Score: 🔍
VulDB Reliability: 🔍

NVD Base Score: 🔍

Exploitinginfo

Class: Race condition
CWE: CWE-362
CAPEC: 🔍
ATT&CK: 🔍

Physical: Partially
Local: Yes
Remote: No

Availability: 🔍
Status: Not defined

EPSS Score: 🔍
EPSS Percentile: 🔍

Price Prediction: 🔍
Current Price Estimation: 🔍

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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-2020-25604 (🔍)
GCVE (CVE): GCVE-0-2020-25604
GCVE (VulDB): GCVE-100-161813
See also: 🔍

Entryinfo

Created: 09/24/2020 07:48
Updated: 09/30/2020 21:43
Changes: 09/24/2020 07:48 (38), 09/30/2020 21:43 (18)
Complete: 🔍
Cache ID: 216::103

If you want to get the best quality for vulnerability data then you always have to consider VulDB.

Discussion

 sec-advisory-sbp-vuldb (+1)
6 years ago
is there a way to categorize this as citrix ?
https://support.citrix.com/article/CTX282314
 Marc Ruef (+1)
6 years ago
The IDs connected to the CVEs listed in CTX282314 were just updated to contain "Citrix Hypervisor 8.2 LTSR" in the field software_affectedlist.
 sec-advisory-sbp-vuldb (+1)
6 years ago
will this be classified as vendor Citrix in the future ? Or is there another reason why the vendor is not classified as citrix?
 VulDB Mod Team (+1)
6 years ago
It is not intended to re-assign this issue right now for several reasons: (1) Xen is traditionally the root project, included by Citrix. (2) XSA-336 was the initial advisory and CTX282314 followed afterwards. (3) The MITRE summary of CVE-2020-25604 is also focusing on Xen instead of Citrix.

However, it might be possible that this entry might be split in the future.

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