Use-after-free in Linux kernel - CVE-2019-15239

Vulnerability identifier: #VU20908

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-2019-15239

CWE-ID: CWE-416

Exploitation vector: Local access

Exploit availability: No public exploit available

The vulnerability allows a local user to cause a denial of service (DoS) condition on a target system.

The vulnerability exists due to multiple use-after-free conditions that exists because of a change to the "net/ipv4/tcp_output.c" file, which was incorrectly backported to earlier long-term versions. A local authenticated user can access the system, execute an application that submits malicious input and crash the software, resulting in a DoS condition.

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

Linux kernel
Red Hat Enterprise Linux for IBM z Systems
Red Hat Enterprise Linux Server
Red Hat Enterprise Linux for Real Time
Red Hat Enterprise Linux for Real Time for NFV
Red Hat Enterprise Linux Workstation
Red Hat Enterprise Linux Desktop
Red Hat Enterprise Linux for Power, big endian
Red Hat Enterprise Linux for Scientific Computing
Red Hat Enterprise Linux for Power, little endian
Red Hat Enterprise Linux for IBM z Systems - Extended Update Support
Red Hat Enterprise Linux for Power, big endian - Extended Update Support
Red Hat Enterprise Linux Server - AUS
Red Hat Enterprise Linux for x86_64 - Extended Update Support
Red Hat Enterprise Linux EUS Compute Node
Red Hat Enterprise Linux for Power, little endian - Extended Update Support
Red Hat Enterprise Linux Server - TUS

kernel (Red Hat package)
kernel-rt (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
Red Hat Virtualization Host
RSA Authentication Manager

Install updates from vendor's website.

Linux kernel - addressed in versions 4.9.190, 4.14.139
kernel (Red Hat package) - update to 3.10.0-1062.7.1.el7
kernel-rt (Red Hat package) - update to 3.10.0-1062.7.1.rt56.1030.el7
RSA Authentication Manager - update to 8.4 Patch 9

• https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=7f582b248d0a86bae5788c548d7bb5bca6f7691a
• https://lore.kernel.org/stable/41a61a2f87691d2bc839f26cdfe6f5ff2f51e472.camel@decadent.org.uk/
• https://pulsesecurity.co.nz/advisories/linux-kernel-4.9-tcpsocketsuaf
• https://salsa.debian.org/kernel-team/kernel-sec/blob/f6273af2d956a87296b6b60379d0a186c9be4bbc/active/CVE-2019-15239
• https://www.debian.org/security/2019/dsa-4497

• Red Hat Enterprise Linux for Real Time update for kernel-rt
• Red Hat Enterprise Linux 7 update for kernel
• Red Hat update for kpatch-patch
• RSA Authentication Manager update for third-party components