Oracle Linux 6 / 7 : Unbreakable Enterprise kernel (ELSA-2019-4808)

medium Nessus Plugin ID 129515


The remote Oracle Linux host is missing one or more security updates.


The remote Oracle Linux 6 / 7 host has packages installed that are affected by multiple vulnerabilities as referenced in the ELSA-2019-4808 advisory.

- An out-of-bounds access issue was found in the Linux kernel, all versions through 5.3, in the way Linux kernel's KVM hypervisor implements the Coalesced MMIO write operation. It operates on an MMIO ring buffer 'struct kvm_coalesced_mmio' object, wherein write indices 'ring->first' and 'ring->last' value could be supplied by a host user-space process. An unprivileged host user or process with access to '/dev/kvm' device could use this flaw to crash the host kernel, resulting in a denial of service or potentially escalating privileges on the system. (CVE-2019-14821)

- In the Linux kernel before 5.2.3, set_geometry in drivers/block/floppy.c does not validate the sect and head fields, as demonstrated by an integer overflow and out-of-bounds read. It can be triggered by an unprivileged local user when a floppy disk has been inserted. NOTE: QEMU creates the floppy device by default. (CVE-2019-14283)

- In the Linux kernel, a certain net/ipv4/tcp_output.c change, which was properly incorporated into 4.16.12, was incorrectly backported to the earlier longterm kernels, introducing a new vulnerability that was potentially more severe than the issue that was intended to be fixed by backporting. Specifically, by adding to a write queue between disconnection and re-connection, a local attacker can trigger multiple use-after-free conditions. This can result in a kernel crash, or potentially in privilege escalation.
NOTE: this affects (for example) Linux distributions that use 4.9.x longterm kernels before 4.9.190 or 4.14.x longterm kernels before 4.14.139. (CVE-2019-15239)

- An issue was discovered in the Linux kernel before 5.0.19. There is an out-of-bounds array access in
__xfrm_policy_unlink, which will cause denial of service, because verify_newpolicy_info in net/xfrm/xfrm_user.c mishandles directory validation. (CVE-2019-15666)

Note that Nessus has not tested for this issue but has instead relied only on the application's self-reported version number.


Update the affected packages.

See Also

Plugin Details

Severity: Medium

ID: 129515

File Name: oraclelinux_ELSA-2019-4808.nasl

Version: 1.4

Type: local

Agent: unix

Published: 10/2/2019

Updated: 9/8/2021

Supported Sensors: Frictionless Assessment Agent, Nessus Agent

Risk Information


Risk Factor: High

Score: 7.4


Risk Factor: Medium

Base Score: 4.6

Temporal Score: 3.4

Vector: AV:L/AC:L/Au:N/C:P/I:P/A:P

Temporal Vector: E:U/RL:OF/RC:C

CVSS Score Source: CVE-2019-15239


Risk Factor: Medium

Base Score: 6.8

Temporal Score: 5.9

Vector: CVSS:3.0/AV:P/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Temporal Vector: E:U/RL:O/RC:C

Vulnerability Information

CPE: cpe:/o:oracle:linux:6, cpe:/o:oracle:linux:7, p-cpe:/a:oracle:linux:kernel-uek, p-cpe:/a:oracle:linux:kernel-uek-debug, p-cpe:/a:oracle:linux:kernel-uek-debug-devel, p-cpe:/a:oracle:linux:kernel-uek-devel, p-cpe:/a:oracle:linux:kernel-uek-doc, p-cpe:/a:oracle:linux:kernel-uek-firmware

Required KB Items: Host/OracleLinux, Host/RedHat/release, Host/RedHat/rpm-list, Host/local_checks_enabled

Exploit Ease: No known exploits are available

Patch Publication Date: 10/1/2019

Vulnerability Publication Date: 7/26/2019

Reference Information

CVE: CVE-2019-14283