![]() ![]() These are easily reversible with tools on the internet and can be reversed within minutes or hours. Credentials using type 5 passwords use a very simple MD5 hashing algorithm.Credentials using type 4 passwords were created by Cisco around 2013 in an attempt to strengthen password, unfortunately, their attempt was severely flawed and resulted in a hash that was weaker than a Type 5 MD5.Steal login credentials on that device for future credential reuse attacks.Having the ability to download and upload Cisco device configurations allows a malicious actor to: Remotely issue Cisco IOS firmware updates.Remotely uploaded a new configuration to the Cisco device.Remotely download the entire start and running configurations of the Cisco device.If Cisco Smart Install is enabled on a Cisco device that is directly connected to the internet it allows a malicious actor to: ZeroNights – Cisco Smart Install Research Presentation.Official Cisco Advisory – Action Required to Secure the Cisco IOS and IOS XE Smart Install Feature.Official Cisco Advisory – Cisco IOS and IOS XE Software Smart Install Remote Code Execution Vulnerability.Office Cisco Advisory – Cisco Smart Install Protocol Misuse.The Smart Install feature incorporates no authentication by design. The feature allows a customer to ship a Cisco switch to any location, install it in the network, and power it on without additional configuration requirements. Note: Cisco has released software updates that address this vulnerability.Cisco Smart Install (SMI) is a “plug-and-play” configuration and image-management feature that provides zero-touch deployment for new (typically access layer) switches. The size and data are taken directly from the network packet and are controlled by an attacker. To be more precise, the buffer overflow takes place in the function smi_ibc_handle_ibd_init_discovery_msg because the size of the data copied to a fixed-size buffer is not checked. When this server is processing a specially crafted malicious message ibd_init_discovery_msg a stack-based buffer overflow occurs. The Smart Install Client starts a server on the TCP(4786) port (opened by default) to interact with the Smart Install Director. During a short scan of the Internet, Nosenko detected 250,000 vulnerable devices and 8,5 million devices that have a vulnerable port open. The vulnerability was presented at the GeekPWN 2017 Hong-Kong by George Nosenko 1 year ago and Cisco was informed about it at the end of September 2017. Role: Client (SmartInstall enabled) Ciscozine-test-2# show vstack config The following examples show the output of the show vstack config command on Cisco Catalyst Switches that are configured as Smart Install clients: Ciscozine-test-1# show vstack config To determine whether a device is configured with the Smart Install client feature enabled, use the show vstack config privileged EXEC command on the Smart Install client. Cisco devices that are configured as a Smart Install director are not affected by this vulnerability. Only Smart Install client switches are affected by the vulnerability that is described in this advisory. ![]() The director can also allocate an IP address and hostname to a client. When a client switch is first installed in the network, the director automatically detects the new switch and identifies the correct Cisco IOS Software image and the configuration file for downloading. The director provides a single management point for images and configuration of client switches. A client switch does not need to be directly connected to the director the client switch can be up to seven hops away. The Smart Install feature incorporates no authentication by design.Ī Smart Install network consists of exactly one Smart Install director switch or router, also known as an integrated branch director (IBD), and one or more Smart Install client switches, also known as integrated branch clients (IBCs). So it allows getting full control over a vulnerable network equipment.Ĭisco Smart Install is a “plug-and-play” configuration and image-management feature that provides zero-touch deployment for new (typically access layer) switches. This vulnerability enables an attacker to remotely execute arbitrary code without authentication. At the end of March, Cisco published a stack-based buffer overflow vulnerability in Smart Install Client code. ![]()
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