Oracle Linux 6 / 7 : Unbreakable Enterprise kernel (ELSA-2018-4096)

high Nessus Plugin ID 109630
New! Plugin Severity Now Using CVSS v3

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Synopsis

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

Description

The remote Oracle Linux 6 / 7 host has packages installed that are affected by multiple vulnerabilities as referenced in the ELSA-2018-4096 advisory.

- A statement in the System Programming Guide of the Intel 64 and IA-32 Architectures Software Developer's Manual (SDM) was mishandled in the development of some or all operating-system kernels, resulting in unexpected behavior for #DB exceptions that are deferred by MOV SS or POP SS, as demonstrated by (for example) privilege escalation in Windows, macOS, some Xen configurations, or FreeBSD, or a Linux kernel crash. The MOV to SS and POP SS instructions inhibit interrupts (including NMIs), data breakpoints, and single step trap exceptions until the instruction boundary following the next instruction (SDM Vol. 3A;
section 6.8.3). (The inhibited data breakpoints are those on memory accessed by the MOV to SS or POP to SS instruction itself.) Note that debug exceptions are not inhibited by the interrupt enable (EFLAGS.IF) system flag (SDM Vol. 3A; section 2.3). If the instruction following the MOV to SS or POP to SS instruction is an instruction like SYSCALL, SYSENTER, INT 3, etc. that transfers control to the operating system at CPL < 3, the debug exception is delivered after the transfer to CPL < 3 is complete. OS kernels may not expect this order of events and may therefore experience unexpected behavior when it occurs.
(CVE-2018-8897)

- kernel KVM before versions kernel 4.16, kernel 4.16-rc7, kernel 4.17-rc1, kernel 4.17-rc2 and kernel 4.17-rc3 is vulnerable to a flaw in the way the Linux kernel's KVM hypervisor handled exceptions delivered after a stack switch operation via Mov SS or Pop SS instructions. During the stack switch operation, the processor did not deliver interrupts and exceptions, rather they are delivered once the first instruction after the stack switch is executed. An unprivileged KVM guest user could use this flaw to crash the guest or, potentially, escalate their privileges in the guest. (CVE-2018-1087)

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

Solution

Update the affected packages.

See Also

https://linux.oracle.com/errata/ELSA-2018-4096.html

Plugin Details

Severity: High

ID: 109630

File Name: oraclelinux_ELSA-2018-4096.nasl

Version: 1.14

Type: local

Agent: unix

Published: 5/9/2018

Updated: 9/8/2021

Dependencies: linux_alt_patch_detect.nasl, ssh_get_info.nasl

Risk Information

CVSS Score Source: CVE-2018-8897

VPR

Risk Factor: Critical

Score: 9.6

CVSS v2

Risk Factor: High

Base Score: 7.2

Temporal Score: 6.3

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

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

CVSS v3

Risk Factor: High

Base Score: 7.8

Temporal Score: 7.5

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

Temporal Vector: E:H/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 Available: true

Exploit Ease: Exploits are available

Patch Publication Date: 5/8/2018

Vulnerability Publication Date: 4/18/2018

Exploitable With

Metasploit (Microsoft Windows POP/MOV SS Local Privilege Elevation Vulnerability)

Reference Information

CVE: CVE-2018-1087, CVE-2018-8897

IAVA: 2018-A-0145-S, 2018-A-0144-S

IAVB: 2018-B-0061-S