SB2021120134 - SUSE update for xen 



SB2021120134 - SUSE update for xen

Published: December 1, 2021

Security Bulletin ID SB2021120134
Severity
Medium
Patch available
YES
Number of vulnerabilities 7
Exploitation vector Remote access
Highest impact Code execution

Breakdown by Severity

Medium 100%
  • Low
  • Medium
  • High
  • Critical

Description

This security bulletin contains information about 7 secuirty vulnerabilities.


1) Use-after-free (CVE-ID: CVE-2021-28702)

The vulnerability allows a remote user to perform a escalate privileges on the system.

The vulnerability exists due to a design error in PCI devices with RMRRs. If such device is connected through to a guest OS, then on guest OS shutdown of the device is not properly deassigned.  The IOMMU configuration for these devices which are not properly deassigned ends up pointing to a freed data structure, including the IO Pagetables.

Subsequent DMA or interrupts from the device will have unpredictable behaviour, ranging from IOMMU faults to memory corruption.

Administrators of guests which have been assigned RMRR-using PCI devices can cause denial of service and other problems, possibly including escalation of privilege.


2) Input validation error (CVE-ID: CVE-2021-28704)

The vulnerability allows a remote attacker to perform a denial of service (DoS) attack.

The vulnerability exists due to an error in XENMEM_decrease_reservation operation. A remote authenticated attacker can pass specially crafted input to the application and perform a denial of service (DoS) attack.


3) Input validation error (CVE-ID: CVE-2021-28705)

The vulnerability allows a remote attacker to perform a denial of service (DoS) attack.

The vulnerability exists due to insufficient validation of user-supplied input in page removal code path. A remote authenticated attacker can pass specially crafted input to the application and perform a denial of service (DoS) attack.


4) Buffer overflow (CVE-ID: CVE-2021-28706)

The vulnerability allows a remote attacker to perform a denial of service (DoS) attack.

The vulnerability exists due to a boundary error. A remote authenticated attacker can trigger memory corruption and cause a denial of service condition on the target system.


5) Input validation error (CVE-ID: CVE-2021-28707)

The vulnerability allows a remote attacker to perform a denial of service (DoS) attack.

The vulnerability exists due to an error in XENMEM_populate_physmap operation. A remote authenticated attacker can pass specially crafted input to the application and perform a denial of service (DoS) attack.


6) Input validation error (CVE-ID: CVE-2021-28708)

The vulnerability allows a remote attacker to perform a denial of service (DoS) attack.

The vulnerability exists due to an error in ENMEM_decrease_reservation operation. A remote authenticated attacker can pass specially crafted input to the application and perform a denial of service (DoS) attack.


7) Input validation error (CVE-ID: CVE-2021-28709)

The vulnerability allows a remote attacker to perform a denial of service (DoS) attack.

The vulnerability exists due to insufficient validation of user-supplied input in insertion of new pages code path. A remote authenticated attacker can pass specially crafted input to the application and perform a denial of service (DoS) attack.


Remediation

Install update from vendor's website.