SB2018052510 - Amazon Linux AMI update for kernel
Published: May 25, 2018 Updated: May 30, 2018
Security Bulletin ID
SB2018052510
Severity
Low
Patch available
YES
Number of vulnerabilities
7
Exploitation vector
Remote access
Highest impact
Code execution
Breakdown by Severity
- Low
- Medium
- High
- Critical
Description
This security bulletin contains information about 7 secuirty vulnerabilities.
1) Improper check or handling of exceptional conditions (CVE-ID: CVE-2018-1087)
The vulnerability allows an adjacent attacker to cause DoS condition or gain elevated privileges on the target system.The weakness exists in the Linux kernel KVM hypervisor due to improper handling of debug exceptions delivered after a stack switch operation via mov SS or pop SS instructions. During the stack switch operation, the exceptions are deferred. An adjacent attacker can cause the service to crash or gain root privileges.
2) Error handling (CVE-ID: CVE-2018-1000199)
The vulnerability allows a local attacker to cause DoS condition on the target system.The weakness exists in the modify_user_hw_breakpoint() function due to error handling flaw. A local attacker can cause the service to crash.
3) Use-after-free error (CVE-ID: CVE-2017-16939)
The vulnerability allows a local attacker to cause DoS condition on the target system.The weakness exists in the XFRM dump policy implementation in net/xfrm/xfrm_user.c in the Linux kernel due to use-after-free error. A local attacker can make a specially crafted SO_RCVBUF setsockopt system call in conjunction with XFRM_MSG_GETPOLICY Netlink messages, trigger memory corruption and cause the service to crash.
Successful exploitation of the vulnerability results in denial of service.
4) Privilege escalation (CVE-ID: CVE-2018-1068)
The vulnerability allows a local attacker to gain elevated privileges on the target system.The weakness exists due to an error in the implementation of 32 bit syscall interface. A local attacker can gain root privileges.
5) Improper initialization (CVE-ID: CVE-2018-1108)
The vulnerability allows a remote attacker to cause DoS condition on the target system.The weakness exists in the crng_ready() function due to improper initialization. A remote attacker can cause the service to crash.
6) Privilege escalation (CVE-ID: CVE-2018-8897)
The vulnerability allows a local attacker to gain elevated privileges on the target system.The vulnerability exists due to improper implementation of Intel 64 and IA-32 Architectures Software Developer's Manual (SDM) on multiple system kernels, which results in an unexpected behavior for #DB exceptions that are deferred by MOV SS or POP SS. A local user can execute arbitrary code with elevated privileges.
7) Denial of service (CVE-ID: CVE-2018-1091)
The vulnerability allows a local attacker to cause DoS condition on the target system.The weakness exists in the flush_tmregs_to_thread function, as defined in the arch/powerpc/kernel/ptrace.c source code, due to a missing processor feature check and an erroneous use of transactional memory (TM) instructions in the core dump path. A local attacker can use unprivileged userspace during a core dump on a POWER host and cause the service to crash.
Remediation
Install update from vendor's website.