Clients Security Questioned

Expert doubts Lotus fixed Sametime flaws.

A security researcher who recently identified vulnerabilities in Lotus Softwares Sametime instant messaging client said the company is being disingenuous about the extent of the flaws and whether theyre fixed in the latest version.

The researcher, who goes by the name Mycelium, said that despite Lotus claims, the vulnerabilities in Sametimes encryption scheme have not been fixed in Version 3.0 and that it is still trivial to recover users keys as well as their passwords. Both a users password and the key used to encrypt the password are sent in the same packet.

"You simply cant send a users credentials somewhere over a network securely unless you either use a key-exchange protocol or you already have a symmetric key agreed on. Windows Sametime 3.0 client does neither," Mycelium said in a post on the BugTraq mailing list last week.

Sametime is used mainly in corporate settings.

Lotus, a division of IBM, did not issue a formal response to the disclosure. However, Ed Brill, one of the Cambridge, Mass., companys marketing executives, addressed it in his blog on the Lotus Web site, saying that the claims are "certainly worth looking into."

Brill disputed Myceliums assertions that the flaws exist in the current version of Sametime and said, "The particular vulnerability being reported hasnt been in a shipping version of Sametime for years."

Sametime, same problems

Security issues in Sametime 3.0:

  • Client sends users password and encryption key in same packet
  • Weak key-generation scheme severely limits number of possible keys
  • Messages open with same 6 bytes every time
"We think its related to an improvement we made to Sametimes encryption in 1.5, but were actively investigating it," said Lotus Senior Marketing Manager Steve Lonergan. "We take security very seriously."

Lotus officials maintain that the encryption problem was fixed in Version 2.0 and that Mycelium analyzed a packet used for reconnections after the original secure key exchange has occurred. "This packet contains no key or password information in any form," officials said in a statement.

In an e-mail interview, Mycelium said Sametimes encryption scheme is essentially a complete failure at protecting user credentials.

"The bottom line is that Sametime is improperly using encryption as a way to merely obfuscate the users credentials," Mycelium said. "They might as well be using ROT13 or a Captain Crunch decoder ring. It would really help if the people at these corporations actually read about the problems before trying to dismiss them as false."

Mycelium said the encryption problems he found are just the beginning of a series of security issues in Sametime that he plans to disclose in the near future.

"The poor programming practices you see illustrated with these bugs are expressed in other, harder-to-find-and-exploit bugs," Mycelium said. "Currently, Im working on investigating [denial-of-service] attacks and buffer overflows in Sametime 3.0."