Red Hat Enterprise Linux 8 update for kernel

1) 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

Red Hat Enterprise Linux for x86_64 - Extended Update Support: 8.2

Red Hat Enterprise Linux Server - AUS: 8.2

Red Hat Enterprise Linux for IBM z Systems - Extended Update Support: 8.2

Red Hat Enterprise Linux for Power, little endian - Extended Update Support: 8.2

Red Hat Enterprise Linux for ARM 64 - Extended Update Support: 8.2

Red Hat Enterprise Linux Server - TUS: 8.2

Red Hat CodeReady Linux Builder for ARM 64: 8.0

Red Hat CodeReady Linux Builder for Power, little endian: 8.0

Red Hat CodeReady Linux Builder for x86_64: 8.0

Red Hat Enterprise Linux for ARM 64: 8

Red Hat Enterprise Linux for Power, little endian: 8

Red Hat Enterprise Linux for IBM z Systems: 8

Red Hat Enterprise Linux for x86_64: 8.0

kernel (Red Hat package): before 4.18.0-193.1.2.el8_2

External links

http://access.redhat.com/errata/RHSA-2020:2102

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.

2) Race condition

EUVDB-ID: #VU28419

Risk: Low

CVSSv3.1: 6.1 [CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C]

CVE-ID: CVE-2020-11884

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

Exploit availability: No

Description

The vulnerability allows a local authenticated user to execute arbitrary code.

In the Linux kernel through 5.6.7 on the s390 platform, code execution may occur because of a race condition, as demonstrated by code in enable_sacf_uaccess in arch/s390/lib/uaccess.c that fails to protect against a concurrent page table upgrade, aka CID-3f777e19d171. A crash could also occur.

Mitigation

Install updates from vendor's website.

Vulnerable software versions

Red Hat Enterprise Linux for x86_64 - Extended Update Support: 8.2

Red Hat Enterprise Linux Server - AUS: 8.2

Red Hat Enterprise Linux for IBM z Systems - Extended Update Support: 8.2

Red Hat Enterprise Linux for Power, little endian - Extended Update Support: 8.2

Red Hat Enterprise Linux for ARM 64 - Extended Update Support: 8.2

Red Hat Enterprise Linux Server - TUS: 8.2

Red Hat CodeReady Linux Builder for ARM 64: 8.0

Red Hat CodeReady Linux Builder for Power, little endian: 8.0

Red Hat CodeReady Linux Builder for x86_64: 8.0

Red Hat Enterprise Linux for ARM 64: 8

Red Hat Enterprise Linux for Power, little endian: 8

Red Hat Enterprise Linux for IBM z Systems: 8

Red Hat Enterprise Linux for x86_64: 8.0

kernel (Red Hat package): before 4.18.0-193.1.2.el8_2

External links

http://access.redhat.com/errata/RHSA-2020:2102

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) Information disclosure

EUVDB-ID: #VU25814

Risk: Low

CVSSv3.1: 3.8 [CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N/E:U/RL:O/RC:C]

CVE-ID: CVE-2020-2732

CWE-ID: CWE-200 - Information exposure

Exploit availability: No

Description

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

The vulnerability exists due to incomplete implementation of vmx_check_intercept on Intel processors in KVM in Linux kernel, which leads to  I/O or MSR interception bitmaps are not checked. A remote attacker with access to guest operating system (e.g. L2 guest) can trick the L0 hypervisor into accessing sensitive information on the L1 hypervisor.

Mitigation

Install updates from vendor's website.

Vulnerable software versions

Red Hat Enterprise Linux for x86_64 - Extended Update Support: 8.2

Red Hat Enterprise Linux Server - AUS: 8.2

Red Hat Enterprise Linux for IBM z Systems - Extended Update Support: 8.2

Red Hat Enterprise Linux for Power, little endian - Extended Update Support: 8.2

Red Hat Enterprise Linux for ARM 64 - Extended Update Support: 8.2

Red Hat Enterprise Linux Server - TUS: 8.2

Red Hat CodeReady Linux Builder for ARM 64: 8.0

Red Hat CodeReady Linux Builder for Power, little endian: 8.0

Red Hat CodeReady Linux Builder for x86_64: 8.0

Red Hat Enterprise Linux for ARM 64: 8

Red Hat Enterprise Linux for Power, little endian: 8

Red Hat Enterprise Linux for IBM z Systems: 8

Red Hat Enterprise Linux for x86_64: 8.0

kernel (Red Hat package): before 4.18.0-193.1.2.el8_2

External links

http://access.redhat.com/errata/RHSA-2020:2102

Q & A

Can this vulnerability be exploited remotely?

Yes. This vulnerability can be exploited by a remote authenticated user via the Internet.

Is there known malware, which exploits this vulnerability?

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