The last password looks random and was still not cracked when the password cracker stopped running three days later. The problem is remembering a password like this one. See the upcoming sidebar, Choosing and Remembering Strong Passwords for tips on choosing an appropriate password.
Except for the enable secret password, all passwords stored on Cisco routers are weakly encrypted. If someone were to get a copy of a router configuration file, it would take only a few seconds to run it through a program to decode all weakly encrypted passwords. The first protection is to keep the configuration files secured.
Encryption on an insecure system, however, provides a false sense of security. If attackers can break into the insecure system, they can set up a key logger and capture everything that is typed on that system. This includes the passwords to decrypt the configuration files. In this case, an attacker just has to wait until the administrator types in the password, and your encryption is compromised.
To use the enable command to access a privilege level, a password must be set for that level. If you try to enter a level with no password, you get the error message No password set. Setting privilege-level passwords can be done with the enable secret level command. The following example enables and sets a password for privilege level 5:
Just as default passwords can be set with either the enable secret or the enable password command, passwords for other privilege levels can be set with the enable password level or enable secret level commands. However, the enable password level command is provided for backward compatibility and should not be used.
In this demonstration, you have seen how we can use John the Ripper to crack MD5 passwords. When using the enable secret command on Cisco IOS devices it is important to use complex passwords that are not based on any string of text and include letters, numbers and special characters.
MD5 hashes are no longer considered secure because attackers can reconstruct valid certificates. This can allow attackers to spoof any website. MD5 is a type 5 password encryption algorithm. see figure below:
Therefore, look at the figure above again, you see type 8 or type 9 passwords, they are the recommended method of configuring all secret passwords (using either) . But both were introduced in Cisco IOS 15.3(3)M and later. They also use SHA encryption and type 9 is slightly stronger than type 8.
Let's look at how to configure type 9 only (same process for type 8), But then, configuring type 9 encryption is not as easy as it may appear. You cannot simply enter enable secret 9 and the unencrypted password as seen in the figure below. To use this form of the command, you must paste in the encrypted password, which can be copied from another router configuration. That's not necessary for this article.
Type 8 and type 9 encryption was also introduced in Cisco IOS 15.3(3)M for the username secret command. Similar to the enable secret command, if you simply enter a user with the username secret command, the default encryption will be MD5. Use the username name algorithm-type command to specify type 9 encryption. The syntax is shown in Figure below along with an example for MD5(type 5) and SHA(type 9).
For backwards compatibility reasons, the enable password, username password, and line password commands are available in the Cisco IOS. These commands use no encryption by default. At best, they can only use type 7 encryption, as shown below. Therefore, not recommended.
To help administrators better secure their environments, the agency published the Cisco Password Types: Best Practices guidance, which breaks down the difficulty of cracking different password protection types on Cisco devices and explains how easy it is to recover the plaintext password in some cases.
In case of type 0 passwords, no encryption or hashing is used, meaning that credentials are stored in plaintext. Type 4 (deprecated since 2013) contains an implementation error that makes it weak in front of brute force attempts. Type 7 passwords, the NSA says, are stored as encoded strings and should be considered obfuscated, rather than encrypted.
Type 6 passwords, which use a reversible 128-bit AES encryption algorithm, are difficult to crack and are more secure than type 7 passwords when the plaintext password is needed on the device. The NSA says that type 6 should always be used for VPN keys, but recommends its use in other cases only if type 8 (and type 9) is not available.
The latest version is faster and contains a lot of new features like APR (ARP Poison Routing) which enables sniffing on switched LANs and Man-in-the-Middle attacks. The sniffer in this version can also analyze encrypted protocols such as SSH-1 and HTTPS and contains filters to capture credentials from a wide range of authentication mechanisms. The new version also ships routing protocols authentication monitors and routes extractors, dictionary and brute-force crackers for all common hashing algorithms and for several specific authentications, password/hash calculators, cryptanalysis attacks, password decoders and some not so common utilities related to network and system security.
Like any other tool its use either good or bad, depends upon the user who uses it. However neither author nor SecurityXploded is in anyway responsible for damages or impact caused due to misuse of Cisco Password Decryptor . Read our complete 'License & Disclaimer' policy here. Release History Version 6.0: 21st June 2018 Mega 2018 release with improved cisco password recovery Version 5.0: 20th Jan 2017 Major 2017 release with fix to critical bug in Cisco password recovery. Version 4.0: 7th Dec 2016 Mega 2016 edition to support for recovering Cisco passwords on Windows 10. Also added new Installer Version 3.0: 30th Jul 2015 New feature added to Installer to dynamically download latest version. Version 2.5: 10th Jan 2015 Integrated Uninstaller into Windows Add/Remove Programs, now you can uninstall it in a standard way. Version 2.0: 2nd Apr 2014 Support for automatically copying the recovered password to clipboard on success. Improved GUI interface with magnifying icon effects. Version 1.5: 21st Apr 2013 Added Copy Button to quickly copy the decrypted password to clipboard Version 1.0: 5th Mar 2013 First public release of Cisco Password Decryptor . Download FREE Download Cisco Password Decryptor v6.0License : FreewarePlatform : Windows XP, 2003, Vista, Windows 7, Windows 8, Windows 10
A password can refer to any string of characters or secret to authenticate an authorized user to a resource. Passwords are typically paired with a username or other mechanism to provide proof of identity.
If the threat actor knows the password length and complexity requirements of the target account, the dictionary is customized to the target. Advanced password crackers often use a dictionary and mix in numbers and symbols to mimic a real-world password with complexity requirements.
6. Implement Password Expiration and Rotation Best Practices: Here the best practices have diverged, depending on whether the passwords are for personal use and/or standard accounts or whether they are for privileged access. NIST advises to avoid changing personal, unless their compromise is in question. On the other hand, privileged passwords, should be routinely changed (rotated). The most sensitive privileged accounts should use one-time-passwords (OTPs), or dynamic secrets, which are expired after each use.
These new kids on the block were introduced in IOS 15.3(3)M which came out way back in July 2013. Although they have been available for a long time I very rarely see customers utilizing these algorithms in their configurations. This might have something to do with another password encryption method (Type 4) which was touted by Cisco back in the day to be the successor to Type 5. Things did not go to plan, and Cisco ended up with a little egg on their faces and had to pull code that supported type 4 encryption. But that might have to be a story for another day.
John the Ripper is a popular password cracking tool that supports many common hash types as well as a useful autodetect feature. It has been around for a while now, and as such, it continues to be one of the strongest and easiest to use crackers available.
We can see that John detects the type of hash used as md5crypt, also known as aix-smd5, and after a bit of time, it completes the session successfully. Now we can use the --show flag to display the cracked passwords that John successfully recovered:
A type of brute force attack, dictionary attacks rely on our habit of picking "basic" words as our password, the most common of which hackers have collated into "cracking dictionaries." More sophisticated dictionary attacks incorporate words that are personally important to you, like a birthplace, child's name, or pet's name.
The first two bytes, 03 , are a randomly generated index into the known cisco key. The remaining bytes in ascii-hex represent the encrypted password. Spacing out the string, 07 52 18 05 00 , you can see the password is 5 characters long. Remember, each character consists of 8 bits. You must XOR each of these with the key in order to get the plaintext.
Configuring usernames and secrets on your Cisco IOS devices is a good practice but one issue we have is scalability. If you have a network with multiple devices, you will have to configure your usernames/secrets on all devices. If you change your password, you have to do it on all devices. 2b1af7f3a8