CVE-2017-3813 : Detail

CVE-2017-3813

7.8
/
High
Authorization problems
A01-Broken Access Control
0.09%V3
Local
2017-02-09
16h00 +00:00
2017-07-24
10h57 +00:00
CVE.org
NVD
Notifications for a CVE
Stay informed of any changes for a specific CVE.
Notifications manage

CVE Descriptions

A vulnerability in the Start Before Logon (SBL) module of Cisco AnyConnect Secure Mobility Client Software for Windows could allow an unauthenticated, local attacker to open Internet Explorer with the privileges of the SYSTEM user. The vulnerability is due to insufficient implementation of the access controls. An attacker could exploit this vulnerability by opening the Internet Explorer browser. An exploit could allow the attacker to use Internet Explorer with the privileges of the SYSTEM user. This may allow the attacker to execute privileged commands on the targeted system. This vulnerability affects versions prior to released versions 4.4.00243 and later and 4.3.05017 and later. Cisco Bug IDs: CSCvc43976.

CVE Informations

Related Weaknesses

CWE-ID Weakness Name 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-862 Missing Authorization
The product does not perform an authorization check when an actor attempts to access a resource or perform an action.

Metrics

Metrics Score Severity CVSS Vector Source
V3.0 7.8 HIGH CVSS:3.0/AV:L/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.

Local

A vulnerability exploitable with Local access means that the vulnerable component is not bound to the network stack, and the attacker's path is via read/write/execute capabilities. In some cases, the attacker may be logged in locally in order to exploit the vulnerability, otherwise, she may rely on User Interaction to execute a malicious file.

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

 [email protected]
V2 7.2 AV:L/AC:L/Au:N/C:C/I:C/A:C [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.
EPSS First.org

Exploit information

Exploit Database EDB-ID : 41476

Publication date : 2017-02-27 23h00 +00:00
Author : Pcchillin
EDB Verified : No

# Exploit Title: Cisco AnyConnect Start Before Logon (SBL) local privilege escalation. CVE-2017-3813 # Date: 02/27/2017 # Exploit Author: @Pcchillin # Software Link: http://www.cisco.com/c/en/us/support/security/anyconnect-secure-mobility-client/tsd-products-support-series-home.html # Version: 4.3.04027 and earlier # Tested on: Windows 10 # CVE : CVE-2017-3813 # Vendor ID : cisco-sa-20170208-anyconnect #Run CMD.EXE with system privileges 1. Start Cisco anyconnect from logon screen. 2. Once the Cisco app comes up (where you can select a profile and hit connect) hold CTRL and hit B. 3. When the Cisco about window appears then select the URL at the bottom. This will open Internet Explorer or you can select Chrome if installed. 4. Once Internet Explorer is started press CTRL-O, then select browse. Chrome press CTRL-O and explorer will open. 5. You can then navigate to the C:\Windows\System32\ folder and find CMD.exe then right click and select RunAsAdministrator. #Run scripts from USB flash drive Follow steps from above and navigate to the flash drive right click and select run. You can also edit the document. Example bat script: Net user #USERNAME #PASSWORD /add Net localgroup administrators #USERNAME /add #Vendor link to advisory: https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20170208-anyconnect #Twitter handle @pcchillin

Products Mentioned

Configuraton 0

Cisco>>Anyconnect_secure_mobility_client >> Version 4.0.00048

    Cisco>>Anyconnect_secure_mobility_client >> Version 4.0.00051

      Cisco>>Anyconnect_secure_mobility_client >> Version 4.0.00052

      Cisco>>Anyconnect_secure_mobility_client >> Version 4.0.00057

      Cisco>>Anyconnect_secure_mobility_client >> Version 4.0.00061

      Cisco>>Anyconnect_secure_mobility_client >> Version 4.1.00028

      Cisco>>Anyconnect_secure_mobility_client >> Version 4.1.02011

      Cisco>>Anyconnect_secure_mobility_client >> Version 4.1.04011

      Cisco>>Anyconnect_secure_mobility_client >> Version 4.1.06013

      Cisco>>Anyconnect_secure_mobility_client >> Version 4.1.06020

      Cisco>>Anyconnect_secure_mobility_client >> Version 4.1.08005

      Cisco>>Anyconnect_secure_mobility_client >> Version 4.2.00096

      Cisco>>Anyconnect_secure_mobility_client >> Version 4.2.01022

      Cisco>>Anyconnect_secure_mobility_client >> Version 4.2.01035

      Cisco>>Anyconnect_secure_mobility_client >> Version 4.2.02075

      Cisco>>Anyconnect_secure_mobility_client >> Version 4.2.03013

      Cisco>>Anyconnect_secure_mobility_client >> Version 4.2.04018

      Cisco>>Anyconnect_secure_mobility_client >> Version 4.2.04039

      Cisco>>Anyconnect_secure_mobility_client >> Version 4.2.05015

      Cisco>>Anyconnect_secure_mobility_client >> Version 4.2.06014

      Cisco>>Anyconnect_secure_mobility_client >> Version 4.3.00748

      Cisco>>Anyconnect_secure_mobility_client >> Version 4.3.01095

      Cisco>>Anyconnect_secure_mobility_client >> Version 4.3.02039

      Cisco>>Anyconnect_secure_mobility_client >> Version 4.3.03086

      Cisco>>Anyconnect_secure_mobility_client >> Version 4.3.04027

      References

      https://www.exploit-db.com/exploits/41476/
      Tags : exploit, x_refsource_EXPLOIT-DB
      http://www.securitytracker.com/id/1037796
      Tags : vdb-entry, x_refsource_SECTRACK
      http://www.securityfocus.com/bid/96145
      Tags : vdb-entry, x_refsource_BID