Debian DSA-4073-1 : linux - security update

high Nessus Plugin ID 105433

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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-2017-8824 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-2017-16538 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-2017-16644 Andrey Konovalov reported that the hdpvr 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-2017-16995 Jann Horn discovered that the Extended BPF verifier did not correctly model the behaviour of 32-bit load instructions. A local user can use this 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-2017-17712 Mohamed Ghannam discovered a race condition in the IPv4 raw socket implementation. A local user could use this to obtain sensitive information from the kernel.

- 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-2017-17862 Alexei Starovoitov discovered that the Extended BPF verifier ignored unreachable code, even though it would still be processed by JIT compilers. This could possibly be used by local users for denial of service. It also increases the severity of bugs in determining unreachable code.

- CVE-2017-17863 Jann Horn discovered that the Extended BPF verifier did not correctly model pointer arithmetic on the stack frame pointer. A local user can use this for privilege escalation.

- CVE-2017-17864 Jann Horn discovered that the Extended BPF verifier could fail to detect pointer leaks from conditional code. A local user could use this to obtain sensitive information in order to exploit other vulnerabilities.

- 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.

The various problems in the Extended BPF verifier can be mitigated by disabling use of Extended BPF by unprivileged users:sysctl kernel.unprivileged_bpf_disabled=1

Debian disables unprivileged user namespaces by default, but if they are enabled (via the kernel.unprivileged_userns_clone sysctl) then CVE-2017-17448 can be exploited by any local user.

Solution

Upgrade the linux packages.

For the stable distribution (stretch), these problems have been fixed in version 4.9.65-3+deb9u1.

Plugin Details

Severity: High

ID: 105433

File Name: debian_DSA-4073.nasl

Version: 3.16

Type: local

Agent: unix

Family: Debian Local Security Checks

Published: 12/26/2017

Updated: 1/4/2021

Supported Sensors: Agentless Assessment, Continuous Assessment, Frictionless Assessment Agent, Nessus Agent, Nessus

Risk Information

VPR

Risk Factor: Critical

Score: 9.7

CVSS v2

Risk Factor: High

Base Score: 7.2

Temporal Score: 6

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

CVSS v3

Risk Factor: High

Base Score: 7.8

Temporal Score: 7.2

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:F/RL:O/RC:C

Vulnerability Information

CPE: cpe:/o:debian:debian_linux:9.0, p-cpe:/a:debian:debian_linux:linux

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: 12/23/2017

Vulnerability Publication Date: 11/4/2017

Exploitable With

Core Impact

Metasploit (Linux BPF Sign Extension Local Privilege Escalation)

Reference Information

CVE: CVE-2017-1000407, CVE-2017-1000410, CVE-2017-16538, CVE-2017-16644, CVE-2017-16995, CVE-2017-17448, CVE-2017-17449, CVE-2017-17450, CVE-2017-17558, CVE-2017-17712, CVE-2017-17741, CVE-2017-17805, CVE-2017-17806, CVE-2017-17807, CVE-2017-17862, CVE-2017-17863, CVE-2017-17864, CVE-2017-8824

DSA: 4073

Detections

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