Thanks for “Stealthful Sniffing, Intrusion Detection and Logging” [LJ, October 2002, also available at www.linuxjournal.com/article/6222]. That is a clever use of Snort, particularly as a means to send logs to a remote host. Just a couple of comments as I read through the article. In the Sidebar titled “LAN Segments, Hubs and Switches” on page 38, it is not impossible to send logs to the Snort logging host from a distant segment. Just ensure the Snort host is attached to a valid IP subnet, and give the subnet's router a static ARP entry that associates the Snort host's MAC address to an unused IP address that is valid for the Snort host's subnet. With the method of logging outlined in the article, it may still be possible to compromise the integrity of the Snort logging host. An attacker may be able to send their own log messages, which may be used either to overflow the logging disk or to attack a potential vulnerability in Snort's capture/parsing logic (if there ever was one).
Mick Bauer replies: Even a stealth logger is vulnerable to denial-of-service (DoS) attacks and sniffer-specific application exploits. But in practical terms, neither of these strikes me as a huge risk. I think it would be pointless for an attacker to aim specifically to take out a stealth logger via a DoS attack; that amount of traffic probably would also take out the system you're actually trying to attack without being logged. On the other hand, we should keep in mind that the “stealth sniffing” technique is intended to mitigate the specific threat of attacks against the logger's local TCP/IP stack and applications. I do think it's useful for that and effectively raises the bar considerably against would-be log-tamperers. However, these are good observations.
I really enjoyed the article “Memory Leak Detection in Embedded Systems” that appeared in the September 2002 issue of Linux Journal. Lately I have been doing a lot of C++ development with the DB2 UDB Administrative API, and detecting memory leaks in both my code and IBM's is useful for debugging purposes. Please feature more articles that address these types of C++ development topics in 2003. An overview of compiler and compiler tools (g++, Intel compilers, etc.) tools would be one article in particular I would like to see run.
—Kevin Wittmer, Senior Software Developer, Expand Beyond, Chicago, Illinois
Watch for an article on the Intel C and C++ compiler next issue.
I recently purchased the new Red Hat 8.0. I have been following Red Hat since 5.1 and have purchased 6.0, 6.1, 7.2 and downloaded 7.3. I find the new desktop, Bluecurve, to be a true bastardization of both Gnome and KDE. Red Hat has removed all of the character from Gnome and KDE and smudged the windowing into their own proprietary look and feel. Konqueror is not the default browser in the KDE menu, and CUPS is not installed by default. If I want to go into KDE, I want KDE. If I want Gnome, give me Gnome, not some smudging of the two. On the other hand, the beauty of open source is that you can do what you want with it as long as you publish the source code, and that is what Red Hat has done. Good for them. But, Bluecurve should be called BLUE-SMUDGE.
—Tom Amon, IT Tech
I love the magazine and enjoy it and sharing GNU/Linux with everyone I know. When I got started with GNU/Linux I looked to books and mags to help me, and what really helped me were any tidbits of information that I could get. Marcel's sections are a blast to read, and maybe something like that more directed to newbies would help other new people in their exploration of GNU/Linux.
If you enjoy sharing your knowledge, please visit our web site (www.linuxjournal.com) for an author's guide, and send us an article proposal.
The key for the EXCLAMATION MARK (!) should be shifted to the key left of the number one (1). This will facilitate typing of the EXCLAMATION MARK (!) without using the Shift key. This is necessary because EXCLAMATION MARK (!) is used very often while typing any text. The key for the QUESTION MARK (?) should be brought down below on the same key on which it is available presently, so that Shift key need not be pressed. The OBLIQUE symbol (/) is very rarely required. Lastly, the INDICATOR LIGHT ON for the CAPS LOCK key, pressed for typing ALL CAPS, is not enough to highlight the same. The INDICATOR LIGHT should not be constant. Instead, it should go on blinking, preferably with a “BEEP BEEP” sound so as to attract the attention of the USER, so that he undoes it after his need to type ALL CAPS is over. I hope, the above-mentioned suggestions are worthy of due consideration and if possible, implementation.
—DR. C.H. AWALGAONKAR
See man xmodmap for how to remap any key to any character.
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