Debian DSA-4082-1 : linux - security update (Meltdown)

High Nessus Plugin ID 105704

Synopsis

The remote Debian host is missing a security-related update.

Description

Several vulnerabilities have been discovered in the Linux kernel that may lead to a privilege escalation, denial of service or information leaks.

- CVE-2017-5754 Multiple researchers have discovered a vulnerability in Intel processors, enabling an attacker controlling an unprivileged process to read memory from arbitrary addresses, including from the kernel and all other processes running on the system.

This specific attack has been named Meltdown and is addressed in the Linux kernel for the Intel x86-64 architecture by a patch set named Kernel Page Table Isolation, enforcing a near complete separation of the kernel and userspace address maps and preventing the attack.
This solution might have a performance impact, and can be disabled at boot time by passing pti=off to the kernel command line.

- CVE-2017-8824 Mohamed Ghannam discovered that the DCCP implementation did not correctly manage resources when a socket is disconnected and reconnected, potentially leading to a use-after-free. A local user could use this for denial of service (crash or data corruption) or possibly for privilege escalation. On systems that do not already have the dccp module loaded, this can be mitigated by disabling it:echo >> /etc/modprobe.d/disable-dccp.conf install dccp false

- CVE-2017-15868 Al Viro found that the Bluebooth Network Encapsulation Protocol (BNEP) implementation did not validate the type of the second socket passed to the BNEPCONNADD ioctl(), which could lead to memory corruption. A local user with the CAP_NET_ADMIN capability can use this for denial of service (crash or data corruption) or possibly for privilege escalation.

- CVE-2017-16538 Andrey Konovalov reported that the dvb-usb-lmedm04 media driver did not correctly handle some error conditions during initialisation. A physically present user with a specially designed USB device can use this to cause a denial of service (crash).

- CVE-2017-16939 Mohamed Ghannam reported (through Beyond Security's SecuriTeam Secure Disclosure program) that the IPsec (xfrm) implementation did not correctly handle some failure cases when dumping policy information through netlink. A local user with the CAP_NET_ADMIN capability can use this for denial of service (crash or data corruption) or possibly for privilege escalation.

- CVE-2017-17448 Kevin Cernekee discovered that the netfilter subsystem allowed users with the CAP_NET_ADMIN capability in any user namespace, not just the root namespace, to enable and disable connection tracking helpers. This could lead to denial of service, violation of network security policy, or have other impact.

- CVE-2017-17449 Kevin Cernekee discovered that the netlink subsystem allowed users with the CAP_NET_ADMIN capability in any user namespace to monitor netlink traffic in all net namespaces, not just those owned by that user namespace.
This could lead to exposure of sensitive information.

- CVE-2017-17450 Kevin Cernekee discovered that the xt_osf module allowed users with the CAP_NET_ADMIN capability in any user namespace to modify the global OS fingerprint list.

- CVE-2017-17558 Andrey Konovalov reported that that USB core did not correctly handle some error conditions during initialisation. A physically present user with a specially designed USB device can use this to cause a denial of service (crash or memory corruption), or possibly for privilege escalation.

- CVE-2017-17741 Dmitry Vyukov reported that the KVM implementation for x86 would over-read data from memory when emulating an MMIO write if the kvm_mmio tracepoint was enabled. A guest virtual machine might be able to use this to cause a denial of service (crash).

- CVE-2017-17805 It was discovered that some implementations of the Salsa20 block cipher did not correctly handle zero-length input. A local user could use this to cause a denial of service (crash) or possibly have other security impact.

- CVE-2017-17806 It was discovered that the HMAC implementation could be used with an underlying hash algorithm that requires a key, which was not intended. A local user could use this to cause a denial of service (crash or memory corruption), or possibly for privilege escalation.

- CVE-2017-17807 Eric Biggers discovered that the KEYS subsystem lacked a check for write permission when adding keys to a process's default keyring. A local user could use this to cause a denial of service or to obtain sensitive information.

- CVE-2017-1000407 Andrew Honig reported that the KVM implementation for Intel processors allowed direct access to host I/O port 0x80, which is not generally safe. On some systems this allows a guest VM to cause a denial of service (crash) of the host.

- CVE-2017-1000410 Ben Seri reported that the Bluetooth subsystem did not correctly handle short EFS information elements in L2CAP messages. An attacker able to communicate over Bluetooth could use this to obtain sensitive information from the kernel.

Solution

Upgrade the linux packages.

For the oldstable distribution (jessie), these problems have been fixed in version 3.16.51-3+deb8u1.

See Also

https://security-tracker.debian.org/tracker/CVE-2017-5754

https://security-tracker.debian.org/tracker/CVE-2017-8824

https://security-tracker.debian.org/tracker/CVE-2017-15868

https://security-tracker.debian.org/tracker/CVE-2017-16538

https://security-tracker.debian.org/tracker/CVE-2017-16939

https://security-tracker.debian.org/tracker/CVE-2017-17448

https://security-tracker.debian.org/tracker/CVE-2017-17449

https://security-tracker.debian.org/tracker/CVE-2017-17450

https://security-tracker.debian.org/tracker/CVE-2017-17558

https://security-tracker.debian.org/tracker/CVE-2017-17741

https://security-tracker.debian.org/tracker/CVE-2017-17805

https://security-tracker.debian.org/tracker/CVE-2017-17806

https://security-tracker.debian.org/tracker/CVE-2017-17807

https://security-tracker.debian.org/tracker/CVE-2017-1000407

https://security-tracker.debian.org/tracker/CVE-2017-1000410

https://security-tracker.debian.org/tracker/source-package/linux

https://packages.debian.org/source/jessie/linux

https://www.debian.org/security/2018/dsa-4082

Plugin Details

Severity: High

ID: 105704

File Name: debian_DSA-4082.nasl

Version: 3.9

Type: local

Agent: unix

Published: 2018/01/10

Updated: 2019/04/05

Dependencies: 12634

Risk Information

Risk Factor: High

CVSS v2.0

Base Score: 7.2

Temporal Score: 6.3

Vector: CVSS2#AV:L/AC:L/Au:N/C:C/I:C/A:C

Temporal Vector: CVSS2#E:H/RL:OF/RC:C

CVSS v3.0

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: CVSS:3.0/E:H/RL:O/RC:C

Vulnerability Information

CPE: p-cpe:/a:debian:debian_linux:linux, cpe:/o:debian:debian_linux:8.0

Required KB Items: Host/local_checks_enabled, Host/Debian/release, Host/Debian/dpkg-l

Exploit Available: true

Exploit Ease: Exploits are available

Patch Publication Date: 2018/01/09

Reference Information

CVE: CVE-2017-1000407, CVE-2017-1000410, CVE-2017-15868, CVE-2017-16538, CVE-2017-16939, CVE-2017-17448, CVE-2017-17449, CVE-2017-17450, CVE-2017-17558, CVE-2017-17741, CVE-2017-17805, CVE-2017-17806, CVE-2017-17807, CVE-2017-5754, CVE-2017-8824

DSA: 4082

IAVA: 2018-A-0019