dmr@alice.UUCP (11/12/88)
Those interested in earlier works of Robert T. Morris, or interested in network security in general, might wish to read AT&T Bell Laboratories CSTR #117, "A Weakness in the 4.2BSD Unix TCP/IP Software," by Robert T. Morris, dated Feb. 25, 1985. An abstract of the abstract: ... [E]ach 4.2BSD system "trusts" some other set of other systems, allowing users logged into trusted systems to execute commands via a TCP/IP network without supplying a password. These notes describe how the design of TCP/IP and 4.2BSD implementation allow users on untrusted and possibly very distant hosts to masquerade as users on trusted hosts. Bell Labs has a growing TCP/IP network connecting machines with varying security needs; perhaps steps should be taken to reduce their vulnerability to each other. This technical report, as well as others, may be ordered by writing to Ellen Stark Room 2C579 AT&T Bell Laboratories 600 Mountain Ave. Murray Hill, NJ 07974 These reports are free of charge. Dennis Ritchie research!dmr dmr@research.att.com
gwyn@smoke.BRL.MIL (Doug Gwyn ) (11/14/88)
In article <8419@alice.UUCP> dmr@alice.UUCP writes: >Those interested in earlier works of Robert T. Morris, >or interested in network security in general, might wish >to read AT&T Bell Laboratories CSTR #117, "A Weakness in the >4.2BSD Unix TCP/IP Software," by Robert T. Morris, >dated Feb. 25, 1985. ... I also recommend this CSTR. By the way, I don't know why the CSTRs are still being made available for free but I'm thankful that they are. Many of them are very good, and they offer one of the few ways of obtaining some insight into what the Bell Labs computer scientists are up to. Our local Internet gurus tell me that the spoofing weakness described in that CSTR is currently harder to exploit, but not impossible. Also an Ethernet seems to be rife with possibilities.. If things get bad enough we may have to resort to end-to-end encryption all the time. What a drag.