What is the CVSS score of CVE-2019-19577?

CVE-2019-19577 has a CVSS 3.1 base score of 7.2 (High). CVSS vector: CVSS:3.1/AV:P/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:H. EPSS exploitation probability: 0.5%.

Is there a patch available for CVE-2019-19577?

Yes, a patch is available for CVE-2019-19577. Update the affected software to the latest version immediately.

Xen CVE-2019-19577

HIGH

Memory Leak (CWE-401)

2019-12-11 cve@mitre.org

Privilege Escalation Denial Of Service Intel Amd Xen Fedora

7.2

CVSS 3.1 · NVD

Severity by source

NVD PRIMARY

7.2 HIGH

AV:P/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:H

Primary rating from NVD · only source for this CVE.

CVSS VectorNVD

CVSS:3.1/AV:P/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:H

Attack Vector

Physical

Attack Complexity

Low

Privileges Required

High

User Interaction

None

Scope

Changed

Confidentiality

High

Integrity

High

Availability

High

Lifecycle Timeline

CVE Published

Dec 11, 2019 - 18:16 nvd

HIGH 7.2

DescriptionNVD

An issue was discovered in Xen through 4.12.x allowing x86 AMD HVM guest OS users to cause a denial of service or possibly gain privileges by triggering data-structure access during pagetable-height updates. When running on AMD systems with an IOMMU, Xen attempted to dynamically adapt the number of levels of pagetables (the pagetable height) in the IOMMU according to the guest's address space size. The code to select and update the height had several bugs. Notably, the update was done without taking a lock which is necessary for safe operation. A malicious guest administrator can cause Xen to access data structures while they are being modified, causing Xen to crash. Privilege escalation is thought to be very difficult but cannot be ruled out. Additionally, there is a potential memory leak of 4kb per guest boot, under memory pressure. Only Xen on AMD CPUs is vulnerable. Xen running on Intel CPUs is not vulnerable. ARM systems are not vulnerable. Only systems where guests are given direct access to physical devices are vulnerable. Systems which do not use PCI pass-through are not vulnerable. Only HVM guests can exploit the vulnerability. PV and PVH guests cannot. All versions of Xen with IOMMU support are vulnerable.

AnalysisAI

An issue was discovered in Xen through 4.12.x allowing x86 AMD HVM guest OS users to cause a denial of service or possibly gain privileges by triggering data-structure access during pagetable-height. Rated high severity (CVSS 7.2), this vulnerability is low attack complexity. This Memory Leak vulnerability could allow attackers to exhaust available memory leading to denial of service.

Technical ContextAI

This vulnerability is classified as Memory Leak (CWE-401), which allows attackers to exhaust available memory leading to denial of service. An issue was discovered in Xen through 4.12.x allowing x86 AMD HVM guest OS users to cause a denial of service or possibly gain privileges by triggering data-structure access during pagetable-height updates. When running on AMD systems with an IOMMU, Xen attempted to dynamically adapt the number of levels of pagetables (the pagetable height) in the IOMMU according to the guest's address space size. The code to select and update the height had several bugs. Notably, the update was done without taking a lock which is necessary for safe operation. A malicious guest administrator can cause Xen to access data structures while they are being modified, causing Xen to crash. Privilege escalation is thought to be very difficult but cannot be ruled out. Additionally, there is a potential memory leak of 4kb per guest boot, under memory pressure. Only Xen on AMD CPUs is vulnerable. Xen running on Intel CPUs is not vulnerable. ARM systems are not vulnerable. Only systems where guests are given direct access to physical devices are vulnerable. Systems which do not use PCI pass-through are not vulnerable. Only HVM guests can exploit the vulnerability. PV and PVH guests cannot. All versions of Xen with IOMMU support are vulnerable. Affected products include: Xen, Fedoraproject Fedora. Version information: through 4.12..

RemediationAI

A vendor patch is available. Apply the latest security update as soon as possible. Ensure all allocated memory is properly freed. Use RAII patterns or garbage-collected languages.