SB20200716127 - Privilege escalation in Xen
Published: July 16, 2020 Updated: July 28, 2020
Security Bulletin ID
SB20200716127
Severity
Low
Patch available
YES
Number of vulnerabilities
1
Exploitation vector
Local access
Highest impact
Code execution
Breakdown by Severity
- Low
- Medium
- High
- Critical
Description
This security bulletin contains information about 1 security vulnerability.
1) Incorrect default permissions (CVE-ID: CVE-2020-15852)
The vulnerability allows a local user to escalate privileges on the system.
An issue was discovered in the Linux kernel 5.5 through 5.7.9, as used
in Xen through 4.13.x for x86 PV guests. An attacker may be granted the
I/O port permissions of an unrelated task. This occurs because
tss_invalidate_io_bitmap mishandling causes a loss of synchronization
between the I/O bitmaps of TSS and Xen. A remote user with access to the guest system can gain elevated privileges.
Remediation
Install update from vendor's website.