-=> Zero Tolerance Technologies (T) Security Advisory <=- Reference: ZTT-SA01-27032001 Author: Richard Scott, r1ccard0@the-pentagon.com Product: Computer Associates' CCC\Harvest Source Code control software http://ca.com/products/ccc_harvest.htm http://ca.com/products/descriptions/ccc_harvest.pdf Severity: High, Application superuser can be obtained. Systems: CCC\Harvest v5.0 running on NT\2000, could also apply to other platforms and versions. Discovered: 26th March 2001 Synopsis CCC Harvest is a tool that is used to audit and maintain access control to source code If the security mechanism is broken, source code can be modified and downloaded with little audit to trail. CCC Harvest has an authentication model that uses TCP to transmit the security credentials to the server for authentication. The encryption method used is susceptible to a chosen plaintext attack. Length of password does not increase the security. No feedback chaining is used to prevent repeated terms in the plaintext appearing in the ciphertext. A user could discover the superuser password in encrypted form and then apply character substitution to reveal the plaintext. Exploit: Using a chosen plain text attack, the character substitution matrix can be constructed. Using this matrix, it is possible to simply look up each ciphertext character to reveal it's plaintext equivalent. The password that was captured using a network analyzer in encrypted form was: yfohoh>u[ghhdptj1111111. Using the matrix above, the resulting plain text would be: ThisismypasswordQQQQQQQ If other characters had been used, it's pretty easy to see how a plain text attack would extend, just feed in the ASCII character set and review the ciphertext that appears. The last few characters also reveal another weakness. The algorithm that is being used, seems to take one character at a time, and doesn't use any loop back mechanism to prevent repeating terms in the plaintext occurring in the ciphertext. Vendor Notification: CCC\Harvest have been notified through their support system, found at : http://support.ca.com/a-g.html I've had a response that all they are willing to say is that this is the current mechanism. There may be some confusion as the extent of the exploit. But I've tried to notify them of the problem. Current research has led me to believe the following: 1) the encryption key is hard coded in to the application 2) the key is the same for all installations of CCC\Harvest As of 27-03-2001 CA are aware of the problem Solution If CCC\Harvest supports NT authentication, it should be used. Changing the key is not a sufficient precaution to prevent this attack. _____________________________________________ Free email with personality! Over 200 domains! http://www.MyOwnEmail.com