Xen up to 4.12.x Incomplete Fix PV Guest race condition

Summaryinfo

A vulnerability was found in Xen up to 4.12.x. It has been classified as problematic. Affected by this issue is some unknown functionality of the component Incomplete Fix. The manipulation as part of PV Guest leads to race condition. This vulnerability is referenced as CVE-2019-19580. Remote exploitation of the attack is possible. No exploit is available.

Detailsinfo

A vulnerability was found in Xen up to 4.12.x (Virtualization Software). It has been rated as critical. This issue affects an unknown code block of the component Incomplete Fix. The manipulation as part of a PV Guest 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 confidentiality, integrity, and availability. The summary by CVE is:

An issue was discovered in Xen through 4.12.x allowing x86 PV guest OS users to gain host OS privileges by leveraging race conditions in pagetable promotion and demotion operations, because of an incomplete fix for CVE-2019-18421. XSA-299 addressed several critical issues in restartable PV type change operations. Despite extensive testing and auditing, some corner cases were missed. A malicious PV guest administrator may be able to escalate their privilege to that of the host. All security-supported versions of Xen are vulnerable. Only x86 systems are affected. Arm systems are not affected. Only x86 PV guests can leverage the vulnerability. x86 HVM and PVH guests cannot leverage the vulnerability. Note that these attacks require very precise timing, which may be difficult to exploit in practice.

The weakness was published 12/11/2019. The identification of this vulnerability is CVE-2019-19580 since 12/04/2019. The attack may be initiated remotely. The requirement for exploitation is a simple authentication. Neither technical details nor an exploit are publicly available. The price for an exploit might be around USD $0-$5k at the moment (estimation calculated on 03/10/2024).

There is no information about possible countermeasures known. It may be suggested to replace the affected object with an alternative product.

Similar entries are available at VDB-147008, VDB-147007, VDB-147006 and VDB-147004. If you want to get the best quality for vulnerability data then you always have to consider VulDB.

Productinfo

Type

• Virtualization Software

Name

• Xen

Version

• 4.0
• 4.1
• 4.2
• 4.3
• 4.4
• 4.5
• 4.6
• 4.7
• 4.8
• 4.9
• 4.10
• 4.11
• 4.12

License

• open-source

CPE 2.3info

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CPE 2.2info

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Entryinfo

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

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