SB2019061722 - Red Hat Enterprise Linux 7.4 Extended Update Support update for kernel



SB2019061722 - Red Hat Enterprise Linux 7.4 Extended Update Support update for kernel

Published: June 17, 2019

Security Bulletin ID SB2019061722
Severity
Medium
Patch available
YES
Number of vulnerabilities 5
Exploitation vector Remote access
Highest impact Denial of service

Breakdown by Severity

Medium 80% Low 20%
  • Low
  • Medium
  • High
  • Critical

Description

This security bulletin contains information about 5 secuirty vulnerabilities.


1) Race condition (CVE-ID: CVE-2018-1000004)

The vulnerability allows a remote attacker to cause DoS condition on the target system.

The weakness exists due to race condition in the sound system. A remote attacker can trigger deadlock and cause the system to crash.

2) Memory corruption (CVE-ID: CVE-2018-7566)

The vulnerability allows a local attacker to write arbitrary files on the target system.

The weakness exists due to out-of-bounds write while ALSA sequencer core initializes the event pool on demand by invoking snd_seq_pool_init() when the first write happens and the pool is empty. A local attacker can trigger buffer overflow and use after free and reset the pool size manually via ioctl concurrently and write arbitrary files.

3) Integer overflow (CVE-ID: CVE-2019-11477)

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

The vulnerability exists due to integer overflow when handling TCP Selective Acknowledgments (SACKs) due to incorrect processing of TCP_SKB_CB(skb)->tcp_gso_segs value in Linux kernel. A remote non-authenticated attacker can send specially crafted network traffic to the affected system, trigger integer overflow and render the system unavailable.

Successful exploitation of the vulnerability allows a remote attacker to perform denial of service (DoS) attack.


4) Resource exhaustion (CVE-ID: CVE-2019-11478)

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

The vulnerability exists due to an error when processing TCP Selective Acknowledgment (SACK) sequences within the Linux kernel TCP retransmission queue implementation in tcp_fragment. A remote non-authenticated attacker can send specially crafted network traffic to the affected system and perform a denial of service (DoS) attack.



5) Resource exhaustion (CVE-ID: CVE-2019-11479)

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

The vulnerability exists due to presence of hard-coded MSS value (48 bytes) in the Linux kernel source code. A remote attacker can fragment TCP resend queues significantly more than if a larger MSS were enforced and perform denial of service (DoS) attack.


Remediation

Install update from vendor's website.