Use-after-free in Linux kernel - CVE-2018-20976

Vulnerability identifier: #VU20917

CSH Severity: Low

CVSS v4: 8.5 [CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N]

CVE-ID: CVE-2018-20976

CWE-ID: CWE-416

Exploitation vector: Local access

Exploit availability: No public exploit available

The vulnerability allows a local user to compromise vulnerable system.

The vulnerability exists in "fs/xfs/xfs_super.c" due to a use-after-free error when the "xfs_fs_fill_super" fails. A local authenticated user can execute arbitrary code on the target system.

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

Linux kernel
Red Hat Enterprise Linux Server - AUS
Red Hat Enterprise Linux Server - TUS
Slackware Linux

kernel (Red Hat package)
Red Hat Enterprise Linux Server for x86_64 - Update Services for SAP Solutions
Red Hat Enterprise Linux Server for Power LE - Update Services for SAP Solutions
linux-4.4.199/kernel-generic
linux-4.4.199/kernel-huge
linux-4.4.199/kernel-modules
linux-4.4.199/kernel-headers
RSA Authentication Manager

Install updates from vendor's website.

Linux kernel - update to 4.18
kernel (Red Hat package) - addressed in versions 3.10.0-327.85.1.el7, 3.10.0-514.72.1.el7
linux-4.4.199/kernel-generic - update to 4.4.199
linux-4.4.199/kernel-huge - update to 4.4.199
linux-4.4.199/kernel-modules - update to 4.4.199
linux-4.4.199/kernel-headers - update to 4.4.199_smp
RSA Authentication Manager - update to 8.4 Patch 9

• https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=c9fbd7bbc23dbdd73364be4d045e5d3612cf6e82

• Red Hat Enterprise Linux Server 7.3 update for kernel
• Red Hat Enterprise Linux 7.2 Advanced Update Support update for kernel
• Slackware Linux update for kernel
• RSA Authentication Manager update for third-party components