Red Hat update for kernel-alt

Published: 2019-09-21

Risk	Low
Patch available	YES
Number of vulnerabilities	3
CVE-ID	CVE-2019-5489 CVE-2019-6974 CVE-2019-13272
CWE-ID	CWE-200 CWE-362 CWE-264
Exploitation vector	Local network
Public exploit	Public exploit code for vulnerability #1 is available. Public exploit code for vulnerability #2 is available. Vulnerability #3 is being exploited in the wild.
Vulnerable software Subscribe	Red Hat Enterprise Linux for IBM System z (Structure A) Operating systems & Components / Operating system Red Hat Enterprise Linux for Power 9 Operating systems & Components / Operating system Red Hat Enterprise Linux for ARM 64 Operating systems & Components / Operating system kernel-alt (Red Hat package) Operating systems & Components / Operating system package or component
Vendor	Red Hat Inc.

Security Bulletin

This security bulletin contains information about 3 vulnerabilities.

1) Information disclosure

EUVDB-ID: #VU16896

Risk: Low

CVSSv3.1: 5.2 [CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N/E:P/RL:U/RC:C]

CVE-ID: CVE-2019-5489

CWE-ID: CWE-200 - Information exposure

Exploit availability: No

Description

The vulnerability allows a local attacker to gain access to potentially sensitive information.

The vulnerability exists due to a flaw in the mincore() implementation in mm/mincore.c. A local attacker can observe page cache access patterns of other processes on the same system and sniff secret information.

Mitigation

Install updates from vendor's website.

Vulnerable software versions

Red Hat Enterprise Linux for IBM System z (Structure A): 7.0

Red Hat Enterprise Linux for Power 9: 7.0

Red Hat Enterprise Linux for ARM 64: 7.0

kernel-alt (Red Hat package): 4.14.0-49.2.2.el7a - 4.14.0-115.10.1.el7a

External links

http://access.redhat.com/errata/RHSA-2019:2809

Q & A

Can this vulnerability be exploited remotely?

No. This vulnerability can be exploited locally. The attacker should have authentication credentials and successfully authenticate on the system.

Is there known malware, which exploits this vulnerability?

No. We are not aware of malware exploiting this vulnerability. However, proof of concept for this vulnerability is available.

2) Race condition

EUVDB-ID: #VU17555

Risk: Low

CVSSv3.1: 7.9 [CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H/E:P/RL:O/RC:C]

CVE-ID: CVE-2019-6974

CWE-ID: CWE-362 - Concurrent Execution using Shared Resource with Improper Synchronization ('Race Condition')

Exploit availability: No

Description

The vulnerability allows an adjacent attacker to gain elevated privileges or cause a denial of service (DoS) condition.

The weakness exists due to exists due to a race condition that causes the kvm_ioctl_create_device function, as defined in the virt/kvm/kvm_main.c source code file of the affected software, to improperly handle reference counting. An adjacent attacker can access the system and execute an application that submits malicious input, trigger a use-after-free condition and cause a targeted guest virtual machine to crash, resulting in a DoS condition. In addition, a successful exploit could allow the attacker to gain elevated privileges on a targeted system.

Mitigation

Install updates from vendor's website.

Vulnerable software versions

Red Hat Enterprise Linux for IBM System z (Structure A): 7.0

Red Hat Enterprise Linux for Power 9: 7.0

Red Hat Enterprise Linux for ARM 64: 7.0

kernel-alt (Red Hat package): 4.14.0-49.2.2.el7a - 4.14.0-115.10.1.el7a

External links

http://access.redhat.com/errata/RHSA-2019:2809

Q & A

Can this vulnerability be exploited remotely?

Yes. This vulnerability can be exploited by a remote non-authenticated attacker via the local network (LAN).

Is there known malware, which exploits this vulnerability?

No. We are not aware of malware exploiting this vulnerability. However, proof of concept for this vulnerability is available.

3) Permissions, Privileges, and Access Controls

EUVDB-ID: #VU19284

Risk: Low

CVSSv3.1: 7.5 [CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:C/C:H/I:H/A:H/E:H/RL:O/RC:C]

CVE-ID: CVE-2019-13272

CWE-ID: CWE-264 - Permissions, Privileges, and Access Controls

Exploit availability: Yes

Description

The vulnerability allows a local user to perform unauthorized actions on a targeted system.

The vulnerability exists when recording the credentials of a process that will create a ptrace relationship in the "ptrace_link" function in the "kernel/ptrace.c" file. A local authenticated user can create a specially crafted application and escalate privileges on the system.

Mitigation

Install updates from vendor's website.

Vulnerable software versions

Red Hat Enterprise Linux for IBM System z (Structure A): 7.0

Red Hat Enterprise Linux for Power 9: 7.0

Red Hat Enterprise Linux for ARM 64: 7.0

kernel-alt (Red Hat package): 4.14.0-49.2.2.el7a - 4.14.0-115.10.1.el7a

External links

http://access.redhat.com/errata/RHSA-2019:2809

Q & A

Can this vulnerability be exploited remotely?

No. This vulnerability can be exploited locally. The attacker should have authentication credentials and successfully authenticate on the system.

Is there known malware, which exploits this vulnerability?

Yes. This vulnerability is being exploited in the wild.