CVSS Meta Temp Score CVSS is a standardized scoring system to determine possibilities of attacks. The Temp Score considers temporal factors like disclosure, exploit and countermeasures. The unique Meta Score calculates the average score of different sources to provide a normalized scoring system.	Current Exploit Price (≈) Our analysts are monitoring exploit markets and are in contact with vulnerability brokers. The range indicates the observed or calculated exploit price to be seen on exploit markets. A good indicator to understand the monetary effort required for and the popularity of an attack.	CTI Interest Score Our Cyber Threat Intelligence team is monitoring different web sites, mailing lists, exploit markets and social media networks. The CTI Interest Score identifies the interest of attackers and the security community for this specific vulnerability in real-time. A high score indicates an elevated risk to be targeted for this vulnerability.
9.0	$0-$5k	0.00

A vulnerability has been found in Cisco IOS and IOS XE (Router Operating System) (the affected version is unknown) and classified as very critical. This vulnerability affects an unknown code of the component Smart Install. The manipulation with an unknown input leads to a improper authentication vulnerability. The CWE definition for the vulnerability is CWE-287. When an actor claims to have a given identity, the product does not prove or insufficiently proves that the claim is correct. As an impact it is known to affect confidentiality, integrity, and availability.

The weakness was released 02/14/2017 as cisco-sr-20170214-smi as confirmed security response (Website). The advisory is available at tools.cisco.com. The public release was coordinated with the vendor. The security response contains:

Several researchers have reported on the use of Smart Install (SMI) protocol messages toward Smart Install clients, also known as integrated branch clients (IBC), allowing an unauthenticated, remote attacker to change the startup-config file and force a reload of the device, load a new IOS image on the device, and execute high-privilege CLI commands on switches running Cisco IOS and IOS XE Software.

The attack can be initiated remotely. No form of authentication is required for a successful exploitation. Technical details are unknown but a public exploit is available. The structure of the vulnerability defines a possible price range of USD $0-$5k at the moment (estimation calculated on 12/05/2019). This vulnerability has a historic impact due to its background and reception. The advisory points out:

Cisco is aware of a significant increase in Internet scans attempting to detect devices where, after completing setup, the Smart Install feature remains enabled and without proper security controls. This could leave the involved devices susceptible to misuse of the feature.

A public exploit has been developed in Python. It is possible to download the exploit at github.com. It is declared as proof-of-concept. As 0-day the estimated underground price was around $25k-$100k. The code used by the exploit is:

req = '0' * 7 + '1' + '0' * 7 + '1' + '0' * 7 + '4' + '0' * 7 + '8' + '0' * 7 + '1' + '0' * 8
resp = '0' * 7 + '4' + '0' * 8 + '0' * 7 + '3' + '0' * 7 + '8' + '0' * 7 + '1' + '0' * 8

print('[INFO] Sending TCP probe to {0}:{1}'.format(args.ip, args.port))

conn.send(req.decode('hex'))

The advisory illustrates:

Cisco does not consider this a vulnerability in Cisco IOS, IOS XE, or the Smart Install feature itself but a misuse of the Smart Install protocol, which does not require authentication by design.

It is possible to mitigate the problem by applying the configuration setting no vstack.Proper firewalling of tcp/4786 is able to address this issue. The best possible mitigation is suggested to be the change of configuration settings. The security response contains the following remark:

Cisco has updated the Smart Install Configuration Guide to include security best practices regarding the deployment of the Cisco Smart Install feature within customer infrastructures.

Additional details are provided at blogs.cisco.com.

Productinfo

Type

• Router Operating System

Vendor

• Cisco

Name

• IOS
• IOS XE

License

• commercial

CVSSv4info

VulDB CVSS-B Score: 🔍
VulDB CVSS-BT Score: 🔍
VulDB Vector: 🔍
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 9.8
VulDB Meta Temp Score: 9.0

VulDB Base Score: 9.8
VulDB Temp Score: 9.0
VulDB Vector: 🔍
VulDB Reliability: 🔍

CVSSv2info

AV	AC	Au	C	I	A
💳	💳	💳	💳	💳	💳
💳	💳	💳	💳	💳	💳
💳	💳	💳	💳	💳	💳

Vector	Complexity	Authentication	Confidentiality	Integrity	Availability
unlock	unlock	unlock	unlock	unlock	unlock
unlock	unlock	unlock	unlock	unlock	unlock
unlock	unlock	unlock	unlock	unlock	unlock

VulDB Base Score: 🔍
VulDB Temp Score: 🔍
VulDB Reliability: 🔍

Exploitinginfo

Class: Improper authentication
CWE: CWE-287
ATT&CK: Unknown

Local: No
Remote: Yes

Availability: 🔍
Access: Public
Status: Proof-of-Concept
Programming Language: 🔍
Download: 🔍
Price Prediction: 🔍
Current Price Estimation: 🔍

0-Day	unlock	unlock	unlock	unlock
Today	unlock	unlock	unlock	unlock

Threat Intelligenceinfo

Interest: 🔍
Active Actors: 🔍
Active APT Groups: 🔍

Countermeasuresinfo

Recommended: Config
Status: 🔍

0-Day Time: 🔍

Config: no vstack
Firewalling: 🔍

Timelineinfo

02/14/2017 🔍
11/09/2017 +268 days 🔍
12/05/2019 +756 days 🔍

Sourcesinfo

Vendor: cisco.com

Advisory: cisco-sr-20170214-smi
Status: Confirmed
Coordinated: 🔍
scip Labs: https://www.scip.ch/en/?labs.20150108
Misc.: 🔍

Entryinfo

Created: 11/09/2017 13:23
Updated: 12/05/2019 11:23
Changes: 11/09/2017 13:23 (54), 12/05/2019 11:23 (2)
Complete: 🔍

Discussion

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