Amazon Linux AMI update for kernel

Published: 2020-07-17

Risk	Medium
Patch available	YES
Number of vulnerabilities	3
CVE-ID	CVE-2020-10711 CVE-2020-12657 CVE-2020-12826
CWE-ID	CWE-476 CWE-416 CWE-190
Exploitation vector	Network
Public exploit	N/A
Vulnerable software Subscribe	Amazon Linux AMI Operating systems & Components / Operating system
Vendor	Amazon Web Services

Security Bulletin

This security bulletin contains information about 3 vulnerabilities.

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

Update the affected packages:

i686:
    kernel-debuginfo-common-i686-4.14.177-107.254.amzn1.i686
    kernel-headers-4.14.177-107.254.amzn1.i686
    kernel-devel-4.14.177-107.254.amzn1.i686
    kernel-tools-4.14.177-107.254.amzn1.i686
    kernel-tools-devel-4.14.177-107.254.amzn1.i686
    kernel-debuginfo-4.14.177-107.254.amzn1.i686
    kernel-4.14.177-107.254.amzn1.i686
    perf-4.14.177-107.254.amzn1.i686
    perf-debuginfo-4.14.177-107.254.amzn1.i686
    kernel-tools-debuginfo-4.14.177-107.254.amzn1.i686

src:
    kernel-4.14.177-107.254.amzn1.src

x86_64:
    kernel-debuginfo-common-x86_64-4.14.177-107.254.amzn1.x86_64
    kernel-tools-debuginfo-4.14.177-107.254.amzn1.x86_64
    kernel-4.14.177-107.254.amzn1.x86_64
    kernel-devel-4.14.177-107.254.amzn1.x86_64
    kernel-tools-devel-4.14.177-107.254.amzn1.x86_64
    kernel-headers-4.14.177-107.254.amzn1.x86_64
    perf-4.14.177-107.254.amzn1.x86_64
    kernel-debuginfo-4.14.177-107.254.amzn1.x86_64
    perf-debuginfo-4.14.177-107.254.amzn1.x86_64
    kernel-tools-4.14.177-107.254.amzn1.x86_64

Vulnerable software versions

Amazon Linux AMI: All versions

External links

http://alas.aws.amazon.com/ALAS-2020-1382.html

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) Use-after-free

EUVDB-ID: #VU28167

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-2020-12657

CWE-ID: CWE-416 - Use After Free

Exploit availability: No

Description

The vulnerability allows a local user to compromise vulnerable system.

The vulnerability exists due to a use-after-free error in "block/bfq-iosched.c" file related to "bfq_idle_slice_timer_body". A local user can execute arbitrary code on the target system.

Successful exploitation of the vulnerability may allow an attacker to compromise vulnerable system.

Mitigation

Update the affected packages:

i686:
    kernel-debuginfo-common-i686-4.14.177-107.254.amzn1.i686
    kernel-headers-4.14.177-107.254.amzn1.i686
    kernel-devel-4.14.177-107.254.amzn1.i686
    kernel-tools-4.14.177-107.254.amzn1.i686
    kernel-tools-devel-4.14.177-107.254.amzn1.i686
    kernel-debuginfo-4.14.177-107.254.amzn1.i686
    kernel-4.14.177-107.254.amzn1.i686
    perf-4.14.177-107.254.amzn1.i686
    perf-debuginfo-4.14.177-107.254.amzn1.i686
    kernel-tools-debuginfo-4.14.177-107.254.amzn1.i686

src:
    kernel-4.14.177-107.254.amzn1.src

x86_64:
    kernel-debuginfo-common-x86_64-4.14.177-107.254.amzn1.x86_64
    kernel-tools-debuginfo-4.14.177-107.254.amzn1.x86_64
    kernel-4.14.177-107.254.amzn1.x86_64
    kernel-devel-4.14.177-107.254.amzn1.x86_64
    kernel-tools-devel-4.14.177-107.254.amzn1.x86_64
    kernel-headers-4.14.177-107.254.amzn1.x86_64
    perf-4.14.177-107.254.amzn1.x86_64
    kernel-debuginfo-4.14.177-107.254.amzn1.x86_64
    perf-debuginfo-4.14.177-107.254.amzn1.x86_64
    kernel-tools-4.14.177-107.254.amzn1.x86_64

Vulnerable software versions

Amazon Linux AMI: All versions

External links

http://alas.aws.amazon.com/ALAS-2020-1382.html

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) Integer overflow

EUVDB-ID: #VU28168

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-2020-12826

CWE-ID: CWE-190 - Integer overflow

Exploit availability: No

Description

The vulnerability allows a local user to execute arbitrary code on the target system.

The vulnerability exists due to integer overflow in "exec_id" in "include/linux/sched.h". A local user can pass specially crafted data to the application, trigger integer overflow and execute arbitrary code on the target system.

Successful exploitation of this vulnerability may result in complete compromise of vulnerable system.

Mitigation

Update the affected packages:

i686:
    kernel-debuginfo-common-i686-4.14.177-107.254.amzn1.i686
    kernel-headers-4.14.177-107.254.amzn1.i686
    kernel-devel-4.14.177-107.254.amzn1.i686
    kernel-tools-4.14.177-107.254.amzn1.i686
    kernel-tools-devel-4.14.177-107.254.amzn1.i686
    kernel-debuginfo-4.14.177-107.254.amzn1.i686
    kernel-4.14.177-107.254.amzn1.i686
    perf-4.14.177-107.254.amzn1.i686
    perf-debuginfo-4.14.177-107.254.amzn1.i686
    kernel-tools-debuginfo-4.14.177-107.254.amzn1.i686

src:
    kernel-4.14.177-107.254.amzn1.src

x86_64:
    kernel-debuginfo-common-x86_64-4.14.177-107.254.amzn1.x86_64
    kernel-tools-debuginfo-4.14.177-107.254.amzn1.x86_64
    kernel-4.14.177-107.254.amzn1.x86_64
    kernel-devel-4.14.177-107.254.amzn1.x86_64
    kernel-tools-devel-4.14.177-107.254.amzn1.x86_64
    kernel-headers-4.14.177-107.254.amzn1.x86_64
    perf-4.14.177-107.254.amzn1.x86_64
    kernel-debuginfo-4.14.177-107.254.amzn1.x86_64
    perf-debuginfo-4.14.177-107.254.amzn1.x86_64
    kernel-tools-4.14.177-107.254.amzn1.x86_64

Vulnerable software versions

Amazon Linux AMI: All versions

External links

http://alas.aws.amazon.com/ALAS-2020-1382.html

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.