Red Hat Enterprise Linux 7 update for kernel

Published: 2020-05-22

Risk	Medium
Patch available	YES
Number of vulnerabilities	3
CVE-ID	CVE-2017-18595 CVE-2019-19768 CVE-2020-10711
CWE-ID	CWE-415 CWE-416 CWE-476
Exploitation vector	Network
Public exploit	N/A
Vulnerable software Subscribe	kernel (Red Hat package) Operating systems & Components / Operating system package or component Red Hat Enterprise Linux Server for x86_64 - Update Services for SAP Solutions Operating systems & Components / Operating system package or component Red Hat Enterprise Linux Server - TUS Operating systems & Components / Operating system Red Hat Enterprise Linux Server - AUS Operating systems & Components / Operating system
Vendor	Red Hat Inc.

Security Bulletin

This security bulletin contains information about 3 vulnerabilities.

1) Double Free

EUVDB-ID: #VU21716

Risk: Low

CVSSv3.1: 6.8 [CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C]

CVE-ID: CVE-2017-18595

CWE-ID: CWE-415 - Double Free

Exploit availability: No

Description

The vulnerability allows a local user to escalate privileges in the system.

The vulnerability exists due to a boundary error within the allocate_trace_buffer() function in the kernel/trace/trace.c. A local user can run a specially crafted application to trigger a double free error and execute arbitrary code on the target system with elevated privileges.

Mitigation

Install updates from vendor's website.

Vulnerable software versions

kernel (Red Hat package): 3.10.0-123.1.2.el7 - 3.10.0-693.65.1.el7

Red Hat Enterprise Linux Server for x86_64 - Update Services for SAP Solutions: 7.4

Red Hat Enterprise Linux Server - TUS: 7.4

Red Hat Enterprise Linux Server - AUS: 7.4

External links

http://access.redhat.com/errata/RHSA-2020:2214

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.

2) Use-after-free

EUVDB-ID: #VU27503

Risk: Low

CVSSv3.1: 6.8 [CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:C/C:H/I:H/A:H/E:U/RL:O/RC:C]

CVE-ID: CVE-2019-19768

CWE-ID: CWE-416 - Use After Free

Exploit availability: No

Description

The vulnerability allows a local user to escalate privileges on the system.

The vulnerability exists due to a use-after-free error in the __blk_add_trace() function in kernel/trace/blktrace.c. A local user can run a specially crafted program, trigger a use-after-free error and execute arbitrary code on the system with elevated privileges.

Mitigation

Install updates from vendor's website.

Vulnerable software versions

kernel (Red Hat package): 3.10.0-123.1.2.el7 - 3.10.0-693.65.1.el7

Red Hat Enterprise Linux Server for x86_64 - Update Services for SAP Solutions: 7.4

Red Hat Enterprise Linux Server - TUS: 7.4

Red Hat Enterprise Linux Server - AUS: 7.4

External links

http://access.redhat.com/errata/RHSA-2020:2214

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.

3) NULL pointer dereference

EUVDB-ID: #VU28180

Risk: Medium

CVSSv3.1: 6.5 [CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H/E:U/RL:O/RC:C]

CVE-ID: CVE-2020-10711

CWE-ID: CWE-476 - NULL Pointer Dereference

Exploit availability: No

Description

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

The vulnerability exists due to a NULL pointer dereference error in the Linux kernel's SELinux subsystem when importing the Commercial IP Security Option (CIPSO) protocol's category bitmap into the SELinux extensible bitmap via the' ebitmap_netlbl_import' routine. While processing the CIPSO restricted bitmap tag in the 'cipso_v4_parsetag_rbm' routine, it sets the security attribute to indicate that the category bitmap is present, even if it has not been allocated.

A remote attacker can send specially crafted packets the affected system, trigger a NULL pointer dereference error and crash the Linux kernel.

Mitigation

Install updates from vendor's website.

Vulnerable software versions

kernel (Red Hat package): 3.10.0-123.1.2.el7 - 3.10.0-693.65.1.el7

Red Hat Enterprise Linux Server for x86_64 - Update Services for SAP Solutions: 7.4

Red Hat Enterprise Linux Server - TUS: 7.4

Red Hat Enterprise Linux Server - AUS: 7.4

External links

http://access.redhat.com/errata/RHSA-2020:2214

Q & A

Can this vulnerability be exploited remotely?

Yes. This vulnerability can be exploited by a remote non-authenticated attacker via the Internet.

Is there known malware, which exploits this vulnerability?

No. We are not aware of malware exploiting this vulnerability.