Amazon Linux AMI update for kernel

1) Null pointer dereference

EUVDB-ID: #VU13853

Risk: Low

CVSSv3.1: 6 [CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:N/I:N/A:H/E:U/RL:U/RC:C]

CVE-ID: CVE-2018-13093

CWE-ID: CWE-476 - NULL Pointer Dereference

Exploit availability: No

Description

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

The vulnerability exists in the lookup_slow() function in the Extended File System (XFS) component, as defined in the source code file fs/xfs/xfs_icache.c due to boundary error when mounting XFS filesystems. A local attacker can mount an XFS filesystem that submits malicious input, trigger NULL pointer dereference memory error and cause the affected software to terminate abnormally.

Mitigation

Update the affected packages.

i686:
    kernel-headers-4.14.59-64.43.amzn1.i686
    kernel-tools-4.14.59-64.43.amzn1.i686
    kernel-debuginfo-common-i686-4.14.59-64.43.amzn1.i686
    kernel-debuginfo-4.14.59-64.43.amzn1.i686
    perf-4.14.59-64.43.amzn1.i686
    kernel-tools-debuginfo-4.14.59-64.43.amzn1.i686
    kernel-4.14.59-64.43.amzn1.i686
    kernel-devel-4.14.59-64.43.amzn1.i686
    perf-debuginfo-4.14.59-64.43.amzn1.i686
    kernel-tools-devel-4.14.59-64.43.amzn1.i686

src:
    kernel-4.14.59-64.43.amzn1.src

x86_64:
    perf-debuginfo-4.14.59-64.43.amzn1.x86_64
    kernel-tools-4.14.59-64.43.amzn1.x86_64
    kernel-debuginfo-common-x86_64-4.14.59-64.43.amzn1.x86_64
    perf-4.14.59-64.43.amzn1.x86_64
    kernel-headers-4.14.59-64.43.amzn1.x86_64
    kernel-4.14.59-64.43.amzn1.x86_64
    kernel-tools-debuginfo-4.14.59-64.43.amzn1.x86_64
    kernel-tools-devel-4.14.59-64.43.amzn1.x86_64
    kernel-devel-4.14.59-64.43.amzn1.x86_64
    kernel-debuginfo-4.14.59-64.43.amzn1.x86_64

Vulnerable software versions

Amazon Linux AMI: All versions

External links

http://alas.aws.amazon.com/ALAS-2018-1048.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.

2) Null pointer dereference

EUVDB-ID: #VU13852

Risk: Low

CVSSv3.1: 6.2 [CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:N/I:N/A:H/E:P/RL:U/RC:C]

CVE-ID: CVE-2018-13094

CWE-ID: CWE-476 - NULL Pointer Dereference

Exploit availability: No

Description

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

The vulnerability exists due to NULL pointer dereference in the fs/xfs/libxfs/xfs_attr_leaf.c source code file in the Extended File System (XFS) component when the xfs_da_shrink_inode() function is called with a NULL byte pointer. A local attacker can mount and perform operations on a crafted XFS image, trigger a NULL pointer dereference condition in the xfs_trans_binval() function and cause the service to crash.

Mitigation

Update the affected packages.

i686:
    kernel-headers-4.14.59-64.43.amzn1.i686
    kernel-tools-4.14.59-64.43.amzn1.i686
    kernel-debuginfo-common-i686-4.14.59-64.43.amzn1.i686
    kernel-debuginfo-4.14.59-64.43.amzn1.i686
    perf-4.14.59-64.43.amzn1.i686
    kernel-tools-debuginfo-4.14.59-64.43.amzn1.i686
    kernel-4.14.59-64.43.amzn1.i686
    kernel-devel-4.14.59-64.43.amzn1.i686
    perf-debuginfo-4.14.59-64.43.amzn1.i686
    kernel-tools-devel-4.14.59-64.43.amzn1.i686

src:
    kernel-4.14.59-64.43.amzn1.src

x86_64:
    perf-debuginfo-4.14.59-64.43.amzn1.x86_64
    kernel-tools-4.14.59-64.43.amzn1.x86_64
    kernel-debuginfo-common-x86_64-4.14.59-64.43.amzn1.x86_64
    perf-4.14.59-64.43.amzn1.x86_64
    kernel-headers-4.14.59-64.43.amzn1.x86_64
    kernel-4.14.59-64.43.amzn1.x86_64
    kernel-tools-debuginfo-4.14.59-64.43.amzn1.x86_64
    kernel-tools-devel-4.14.59-64.43.amzn1.x86_64
    kernel-devel-4.14.59-64.43.amzn1.x86_64
    kernel-debuginfo-4.14.59-64.43.amzn1.x86_64

Vulnerable software versions

Amazon Linux AMI: All versions

External links

http://alas.aws.amazon.com/ALAS-2018-1048.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. However, proof of concept for this vulnerability is available.