CVE-2017-3819 : Détail

CVE-2017-3819

8.8
/
Haute
Authorization problems
A01-Broken Access ControlA07-Identif. and Authent. Fail
0.2%V3
Network
2017-03-15
19h00 +00:00
2017-07-11
07h57 +00:00
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Descriptions du CVE

A privilege escalation vulnerability in the Secure Shell (SSH) subsystem in the StarOS operating system for Cisco ASR 5000 Series, ASR 5500 Series, ASR 5700 Series devices, and Cisco Virtualized Packet Core could allow an authenticated, remote attacker to gain unrestricted, root shell access. The vulnerability is due to missing input validation of parameters passed during SSH or SFTP login. An attacker could exploit this vulnerability by providing crafted user input to the SSH or SFTP command-line interface (CLI) during SSH or SFTP login. An exploit could allow an authenticated attacker to gain root privileges access on the router. Note: Only traffic directed to the affected system can be used to exploit this vulnerability. This vulnerability can be triggered via both IPv4 and IPv6 traffic. An established TCP connection toward port 22, the SSH default port, is needed to perform the attack. The attacker must have valid credentials to login to the system via SSH or SFTP. The following products have been confirmed to be vulnerable: Cisco ASR 5000/5500/5700 Series devices running StarOS after 17.7.0 and prior to 18.7.4, 19.5, and 20.2.3 with SSH configured are vulnerable. Cisco Virtualized Packet Core - Single Instance (VPC-SI) and Distributed Instance (VPC-DI) devices running StarOS prior to N4.2.7 (19.3.v7) and N4.7 (20.2.v0) with SSH configured are vulnerable. Cisco Bug IDs: CSCva65853.

Informations du CVE

Faiblesses connexes

CWE-ID Nom de la faiblesse Source
CWE-264 Category : Permissions, Privileges, and Access Controls
Weaknesses in this category are related to the management of permissions, privileges, and other security features that are used to perform access control.
CWE-306 Missing Authentication for Critical Function
The product does not perform any authentication for functionality that requires a provable user identity or consumes a significant amount of resources.

Métriques

Métriques Score Gravité CVSS Vecteur Source
V3.0 8.8 HIGH CVSS:3.0/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/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.

Low

The attacker is authorized with (i.e. requires) privileges that provide basic user capabilities that could normally affect only settings and files owned by a user. Alternatively, an attacker with Low privileges may have the ability to cause an impact only to non-sensitive resources.

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.

High

There is total loss of confidentiality, resulting in all resources within the impacted component being divulged to the attacker. Alternatively, access to only some restricted information is obtained, but the disclosed information presents a direct, serious impact. For example, an attacker steals the administrator's password, or private encryption keys of a web server.

Integrity Impact

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

High

There is a total loss of integrity, or a complete loss of protection. For example, the attacker is able to modify any/all files protected by the impacted component. Alternatively, only some files can be modified, but malicious modification would present a direct, serious consequence to 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

nvd@nist.gov
V2 9 AV:N/AC:L/Au:S/C:C/I:C/A:C nvd@nist.gov

EPSS

EPSS est un modèle de notation qui prédit la probabilité qu'une vulnérabilité soit exploitée.

Score EPSS

Le modèle EPSS produit un score de probabilité compris entre 0 et 1 (0 et 100 %). Plus la note est élevée, plus la probabilité qu'une vulnérabilité soit exploitée est grande.

Percentile EPSS

Le percentile est utilisé pour classer les CVE en fonction de leur score EPSS. Par exemple, une CVE dans le 95e percentile selon son score EPSS est plus susceptible d'être exploitée que 95 % des autres CVE. Ainsi, le percentile sert à comparer le score EPSS d'une CVE par rapport à d'autres CVE.

Products Mentioned

Configuraton 0

Cisco>>Asr_5000_series_software >> Version 18.0.0

    Cisco>>Asr_5000_series_software >> Version 18.0.0.57828

      Cisco>>Asr_5000_series_software >> Version 18.0.0.59167

        Cisco>>Asr_5000_series_software >> Version 18.0.0.59211

          Cisco>>Asr_5000_series_software >> Version 18.0.l0.59219

            Cisco>>Asr_5000_series_software >> Version 18.1.0

              Cisco>>Asr_5000_series_software >> Version 18.1.0.59776

                Cisco>>Asr_5000_series_software >> Version 18.1.0.59780

                  Cisco>>Asr_5000_series_software >> Version 18.1_base

                    Cisco>>Asr_5000_series_software >> Version 18.3.0

                      Cisco>>Asr_5000_series_software >> Version 18.3_base

                        Cisco>>Asr_5000_series_software >> Version 18.4.0

                        Cisco>>Asr_5000_series_software >> Version 19.0.1

                        Cisco>>Asr_5000_series_software >> Version 19.0.m0.60737

                          Cisco>>Asr_5000_series_software >> Version 19.0.m0.60828

                            Cisco>>Asr_5000_series_software >> Version 19.0.m0.61045

                              Cisco>>Asr_5000_series_software >> Version 19.1.0

                                Cisco>>Asr_5000_series_software >> Version 19.1.0.61559

                                  Cisco>>Asr_5000_series_software >> Version 19.2.0

                                    Cisco>>Asr_5000_series_software >> Version 19.3.0

                                    Cisco>>Asr_5000_series_software >> Version 20.0.0

                                    Cisco>>Virtualized_packet_core >> Version v18.0_base

                                      Cisco>>Virtualized_packet_core >> Version v19.0_base

                                        Cisco>>Virtualized_packet_core >> Version v20.0_base

                                          Références

                                          http://www.securityfocus.com/bid/96913
                                          Tags : vdb-entry, x_refsource_BID
                                          http://www.securitytracker.com/id/1038050
                                          Tags : vdb-entry, x_refsource_SECTRACK