SB2018122109 - Amazon Linux AMI update for kernel
Published: December 21, 2018
Breakdown by Severity
- Low
- Medium
- High
- Critical
Description
This security bulletin contains information about 3 secuirty vulnerabilities.
1) Null pointer dereference (CVE-ID: CVE-2018-19407)
The vulnerability allows a remote attacker to cause DoS condition on the target system.
The vulnerability exists in the vcpu_scan_ioapic function, as defined in the arch/x86/kvm/x86.c source code file due to the failure of the I/O Advanced Programmable Interrupt Controller (I/O APIC) to initialize. A local attacker can access the system and execute an application that submits malicious system calls, trigger a NULL pointer dereference, which could result in a DoS condition.
2) Information disclosure (CVE-ID: CVE-2018-18710)
The vulnerability allows a remote attacker to obtain potentially sensitive information.
The vulnerability exists in the cdrom_ioctl_select_disc function, as defined in the drivers/cdrom/cdrom.c source code file due to boundary error when processing of user-supplied input. A local attacker can access the system, execute an application that submits malicious input to read arbitrary kernel memory on the system, which could be used to conduct additional attacks.
3) Security restrictions bypass (CVE-ID: CVE-2018-16862)
The vulnerability allows a local attacker to bypass security restrictions on the target system.
The vulnerability exists due to an error when the cleancache subsystem clears an inode after the final file truncation (removal). A local attacker can supply new file created with the same inode that may contain leftover pages from cleancache and bypass security restrictions to conduct further attacks.
Remediation
Install update from vendor's website.