| .oO Phrack 50 Oo. | |
| Volume Seven, Issue Fifty | |
| 3 of 16 | |
| // // /\ // ==== | |
| // // //\\ // ==== | |
| ==== // // \\/ ==== | |
| /\ // // \\ // /=== ==== | |
| //\\ // // // // \=\ ==== | |
| // \\/ \\ // // ===/ ==== | |
| ------------------------------------------------------------------------------ | |
| ----<>---- | |
| =--=--=--=--=--=--=--= | |
| Portable BBS Hacking | |
| by: Khelbin | |
| =--=--=--=--=--=--=--= | |
| This hack basically has little to do with the BBS software itself but | |
| with the archiver which is being used. I've used this technique on a | |
| mock Renegade setup and with pkzip/pkunzip as the archiver. I'm sure | |
| that this same type of technique will be successful on many other BBS | |
| platforms and with other archivers as well. While explaining this, I will | |
| use Renegade and pkzip/pkunzip as my example. | |
| A Renegade setup is most likely vulnerable if it will pkunzip any user | |
| supplied zipfile. This is because Renegade's default command to unzip files | |
| is "pkunzip -do <filename>". The -d flag unzips the file retaining any | |
| directories which were included into the zip file and the -o flag will | |
| automatically overwrite any file. | |
| Suppose the remote system is also setup in a normal Renegade fashion. | |
| Let's use this file tree as an example: | |
| C:\RENEGADE\ | |
| C:\RENEGADE\TEMP\ | |
| C:\RENEGADE\DATA\ | |
| The other subdirectories are unimportant for our discussion. Suppose | |
| that C:\TEMP is where our uploaded file will go for it to be unzipped and | |
| then scanned for viruses. C:\RENEGADE\DATA\ is where the USERS.DAT file | |
| is stored, containing all the users login information. | |
| Wouldn't it be nice if we could put our own USERS.DAT in there instead? | |
| To do this, you must first generate a USERS.DAT file. This is easy enough. | |
| Just download a copy of Renegade which is the same version as the target | |
| machine and then use the user editor to make a "SYSOP" account with the | |
| password "SYSOP" (this should be the default anyway on the USERS.DAT file). | |
| Here's how we prepare the zipfile on our own machine: | |
| C:\>md tmp | |
| C:\>md c:\tmp\ddsdata | |
| C:\>copy c:\renegade\data\users.dat c:\tmp\ddsdata | |
| C:\>cd tmp | |
| C:\TMP>pkzip -pr evil.zip | |
| Now we get out our trusty hex editor and edit evil.zip. Change every | |
| occurrence of "ddsdata" in evil.zip to read "../data" and make sure that the | |
| slash is a forward-slash and not a back-slash. Now when you upload | |
| evil.zip to this particular BBS, it will expand to "../data/users.dat" | |
| and your USERS.DAT file will overwrite their USERS.DAT file since the -od | |
| flag is default on Renegade. | |
| Now you can login as SYSOP with a password SYSOP and do as you please. | |
| You could also overwrite virtually any file on a BBS like this and believe | |
| me, many do have this vulnerability or something very close to it. You are | |
| only limited in how much you can traverse up and down directories by DOS's | |
| maximum file length of 12 (8 plus "." plus 3 = 12). I quickly tried | |
| inserting a few blocks into the zipfile in order to produce a limitless | |
| amount of traversing which but it seemed to corrupt the file for some | |
| reason. | |
| Removing the -o flag is not a fix for this bug. Without the -o flag, | |
| you can "hang" the system in a denial of service attack. By again hex | |
| editing the names of the files within your evil.zip, you can make it have | |
| two files with the same name. When it tries to unzip the second file, it | |
| will prompt locally whether to overwrite the file or not and "hang" the | |
| board. Instead, the -d flag is what should be removed. | |
| This is just an example as I'm sure many other BBS systems do this same | |
| type of uncompressing. I'd also bet that arj, lha, and several others, can | |
| also be hex edited and yield similar results. Either way, it's either take | |
| out the "restore/create directories within archive" option or pay the price. | |
| ----<>---- | |
| German Hacker "Luzifer" convicted by SevenUp / sec@sec.de | |
| ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ | |
| SYNOPSIS | |
| ======== | |
| On February 5th, 1997, Wilfried Hafner aka "Luzifer" was sentenced to | |
| three years incarceration - no parole, no probation. I've got the story | |
| for you right from the courtroom in Munich, Germany. This is one of the | |
| first ever cases in which a hacker in Germany actually gets convicted, so | |
| it's particularly interesting. (Although the court and I use the term | |
| "hacking", this is actually a case of unethical electronic fraud.) | |
| LUZIFER | |
| ======= | |
| Wilfried Hafner (Luzifer) was born on April 6, 1972, in Breschau Italy. | |
| According to his own circulum vitae, which he quoted in court himself, | |
| he's been a pretty smart guy: He started programming at 8 years,and cracked | |
| about 600 Commodore programs, at 14, got a modem and then started a BBS. | |
| In 1990 he was blueboxing to some overseas partylines to communicate with | |
| others. But he didn't seem to use any other "elite" chat systems like x.25 | |
| or IRC, so most people (including myself) didn't know him that well. In | |
| 1992 he moved to South Germany to goto school. | |
| WHAT HE DID | |
| =========== | |
| Luzifer set up some overseas partylines in the Dominican Republic, | |
| Indonesia, The Philippines, and Israel. Some lines included live chat, | |
| but most were just sex recordings. Then he used a local company PBX (a | |
| Siemens Hicom 200 model), from his homeline, which was only "protected" | |
| by a one digit code, to dialout to his partylines and his girlfriend in | |
| Chile. He also was blueboxing (which the prosecution calls "C5-hacking") | |
| from five lines simultaneously, mostly via China. To trick the partyline | |
| provider and overseas telcos (who are aware of computer-generated calls) | |
| he wrote a little program that would randomize aspects of the calls | |
| (different calling intervals and different durations for the calls). | |
| He got arrested the first time on 03/29/95, but was released again after | |
| 13 days. Unfortunately he restarted the phreaking right away. If he'd | |
| had stopped then, he would just have gotten 1 year probation. However, he | |
| was arrested again in January 1996, and has been in prison since. | |
| Here are some numbers (shouts to Harper(tm)'s Index): | |
| - Number of logged single phone connections: 18393 | |
| - Profit he makes for 1 min. partyline calls: US$ 0.35 - 0.50 | |
| - Total Damage (= lost profit of telco): US$ 1.15 Million | |
| - Money that Luzifer got from the partylines: US$ 254,000 | |
| - Paragraph in German Law that covers this fraud: 263a StG | |
| - Duration of all calls, if made sequentially: 140 days | |
| THE TRIAL | |
| ========= | |
| This trial was far less spectacular than OJ's. While 7 days had been | |
| scheduled, the trial was over after the second day. The first day went | |
| quite quick: The court didn't have enough judges available (two were present, | |
| but three required), so it had to be postponed after some minutes. | |
| At the second day, both, the prosecution and Luzifers two lawyers, made | |
| a deal and plead guilty for three years prison (but no financial punitive). | |
| In Germany, all sentences over two years cannot be carried out on probation. | |
| But he has been allowed the use of a notebook computer. Rumor has it that | |
| he might be get an "open" execution, meaning that he has to sleep in the | |
| prison at night, but can work or study during the day. | |
| The deal looked like the prosecution dropped all counts (including | |
| the one abusing the PBX in the first place) but two: one for the blueboxing | |
| before getting arrested, and one count for blueboxing afterwards. They don't | |
| treat all 18393 connections as a separate count, but just each start of the | |
| "auto-call-program". | |
| QUOTES | |
| ====== | |
| Here are some interesting and funny quotes from the trial: | |
| "Just for fun and technical curiosity" - Defendant | |
| "Wouldn't one line be enough for technical experience"? - Judge | |
| "I ordered 21 lines, but just got 5" - Defendant | |
| "Lots of criminal energy" - Prosecutor | |
| "He's obsessed and primarily competing with other hackers" - Lawyer | |
| "A generation of run down computer kids" - Prosecutor | |
| "He may keep the touchtone dialer, but we cannot return his laser fax, | |
| because the company's PBX number is stored in its speedial" - Prosecutor | |
| "Myself and the Telekom have learned a lot" - Prosecutor | |
| "New cables must be installed, new satelites have to be shot into the air" | |
| - Prosecutor about the consequences of used up trunks and intl. lines | |
| "The German Telekom is distributing pornography with big profits" - Lawyer | |
| ----<>---- | |
| Yet another Lin(s)ux bug! | |
| By: Xarthon | |
| IP_MASQ is a commonly used new method of traffic forwarding which | |
| may be enabled in newer Linux kernel versions. I have been doing some | |
| research into this new feature. | |
| IP_MASQ fails to check to make sure that a packet is in the non | |
| routable range. If you are able to get any packet to its destination, the | |
| header of that packet is rewritten. | |
| Because of the lack of non-routable ip checking, the same tactics | |
| that would be used a gateway machine, may also be used on a machine that | |
| uses ip_masq. | |
| So in conclusion, you are able to spoof as if you are on the | |
| inside network, from the outside. But hey, what can you expect from | |
| Linux? | |
| ----<>---- | |
| 11.22.96 | |
| daemon9 and w0zz's adventure into warez-pup land... | |
| *W|ZaRD* u there? | |
| -> *W|ZaRD* yes? | |
| <w0zz> d9 | |
| <d9> hi w0zz | |
| *W|ZaRD* r u the prez of BREED? | |
| *** |COBRA| invites you to channel #supreme | |
| <d9> I am hungry | |
| -> *W|ZaRD* yup | |
| *_e|f_* hi there - you got a minute? | |
| *W|ZaRD* alright.. i got a question for u... | |
| *** d9 (plugHead@onyx.infonexus.com) has joined channel #supreme | |
| *** Topic for #supreme: [SpR] Still in discussion phase! [SpR] | |
| *** #supreme _e|f_ 848703589 | |
| *** Users on #supreme: d9 @{Imagine} @BL|ZZaRD @W|ZaRD @|COBRA| @_e|f_ | |
| <_e|f_> re d9 | |
| *** Mode change "+o d9" on channel #supreme by _e|f_ | |
| <|COBRA|> today is going to be a bad day :( | |
| *W|ZaRD* would you be interested in merging with like 4-6 other groups to become 1 group.?? | |
| *W|ZaRD* i mean. all the other groups have like 11 sitez and 8-10 suppliers like NGP | |
| *W|ZaRD* and if we merge we could be up there with Prestige, and Razor | |
| <_e|f_:#supreme> hello d9 | |
| <d9> *W|ZaRD* i mean. all the other groups have like 11 sitez and 8-10 suppliers like NGP | |
| -> *W|ZaRD* hmm | |
| *** Inviting w0zz to channel #supreme | |
| <_e|f_> we got a discussion going on here for big plans for a lot of us "smaller" groups (smaller as | |
| compared to razor, prestige etc) :) | |
| <d9> ah | |
| *** Mystic12 (NONE@wheat-53.nb.net) has joined channel #supreme | |
| <_e|f_> this is all still in discussion stages | |
| <w0zz:#!r00t> hahahaha | |
| *** Mode change "+o Mystic12" on channel #supreme by W|ZaRD | |
| <_e|f_:#supreme> but would you be interested in a joint venture between a few of us smaller release groups | |
| to combine into one large release group - to challenge razor and prestige? | |
| <d9> w0zz | |
| <w0zz> you've been sucked into warez kiddie conspiracies | |
| <d9> join me | |
| <w0zz:#!r00t> where are you? | |
| *** Inviting w0zz to channel #supreme | |
| *** w0zz (wozz@big.wookie.net) has joined channel #supreme | |
| <d9> well... | |
| *** Mode change "+o w0zz" on channel #supreme by d9 | |
| <w0zz> werd | |
| <_e|f_> re wozz | |
| <d9> hi w0zz | |
| <w0zz> hi there | |
| <_e|f_> i can send u a log to flesh out a few more details if you like | |
| <w0zz> i've got mackin' warez | |
| <d9> hmm | |
| <d9> sure | |
| *w0zz* you recording this for line noise ? | |
| *w0zz* ;) | |
| -> *w0zz* indeed...;) | |
| *w0zz* heh | |
| <d9> the thing is, I have all this porn I want to unload... | |
| <w0zz> yah, i got da mackin porn too | |
| <d9> but, no good place to distro it... | |
| *** ^DRiFTeR^ (~Drifter@203.30.237.48) has joined channel #supreme | |
| *** Mode change "+o ^DRiFTeR^" on channel #supreme by _e|f_ | |
| <_e|f_> hey drifter | |
| <d9> I was using this panix account, but all that SYN flooding stopped that cold... | |
| <_e|f_> drifter is muh vp :) | |
| <RAgent:#!r00t> do you even know what BREED is, route? | |
| <d9> warez pups? | |
| <_e|f_:#supreme> drifter: d9 and wozz are from breed | |
| <_e|f_:#supreme> blizzard and wizard are from NGP | |
| <^DRiFTeR^:#supreme> k | |
| <d9:#!r00t> HAHAHAhahahaha | |
| <Mystic12:#supreme> I am also from NGP | |
| *** Signoff: Mystic12 (Leaving) | |
| <W|ZaRD:#supreme> so is Mystic12 | |
| <RAgent:#!r00t> well, looks like it. just wondered if you knew them at all | |
| <d9> w0zz... you get the new shit I send you? | |
| *** Mystic12 (NONE@wheat-53.nb.net) has joined channel #supreme | |
| <w0zz:#supreme> yah | |
| <_e|f_:#supreme> sorry mystic - didnt see yew there | |
| <d9:#!r00t> nope! | |
| *** Mode change "+o Mystic12" on channel #supreme by W|ZaRD | |
| <w0zz> indexed and everything | |
| <RAgent:#!r00t> hahaha | |
| <w0zz> i spanked my monkey for hours | |
| <RAgent:#!r00t> whee | |
| <d9> werd. | |
| <d9:#!r00t> AAAAAHAHAHahahhahaha WOZZ! | |
| <_e|f_> brb | |
| <d9> hmm | |
| #supreme Mystic12 H@ NONE@wheat-53.nb.net (CCINC) | |
| #supreme ^DRiFTeR^ H@ ~Drifter@203.30.237.48 (ReaLMS oF Da NiTe - HrD) | |
| #supreme w0zz H@ wozz@big.wookie.net (w0zz) | |
| #supreme d9 H@ plugHead@onyx.infonexus.com (Built Demon Tough) | |
| #supreme {Imagine} H@ BOB@199.190.110.99 (.:tORn f#E?h:. v1.45 by SLaG) | |
| #supreme BL|ZZaRD H@ blizzard@ip222.tol.primenet.com (hehe) | |
| #supreme W|ZaRD H@ m3ntal@ip201.tol.primenet.com (M3NTaL) | |
| #supreme |COBRA| H@ cobra@slbri3p24.ozemail.com.au (100% ReVpOwEr) | |
| #supreme _e|f_ H@ _e|f_@203.26.197.12 (blah) | |
| <w0zz:#!r00t> werd | |
| *** Mode change "-ooo _e|f_ |COBRA| W|ZaRD" on channel #supreme by d9 | |
| *** Mode change "-ooo BL|ZZaRD w0zz ^DRiFTeR^" on channel #supreme by d9 | |
| *** Mode change "-o Mystic12" on channel #supreme by d9 | |
| <W|ZaRD> hehe | |
| *** Mode change "+o w0zz" on channel #supreme by d9 | |
| <_e|f_> sigh | |
| <W|ZaRD> what would the new group name be.. if this happened? | |
| <d9> the new name? | |
| <W|ZaRD> hmm. nice takeover | |
| <W|ZaRD> hehe | |
| <w0zz> werd | |
| <d9> w0zz, what do you think? | |
| <W|ZaRD> new group name | |
| <_e|f_> d9: ops plz | |
| <d9> r00t? guild? | |
| <d9> wait | |
| <_e|f_> this is only a temp channel neway d9 | |
| <W|ZaRD> guild wuz already used | |
| <d9> those are taken... | |
| <_e|f_> so its a waste to do a takeover | |
| <w0zz> i like r00t | |
| <w0zz> oh | |
| <w0zz> yeah | |
| <w0zz> those guys are eleet | |
| <d9> yah | |
| <d9> I hear r00t has this 10 year old that can break into .mil sites... | |
| *** d9 is now known as daemon9 | |
| <w0zz> duod, he's like D.A.R.Y.L. | |
| <W|ZaRD> hehe | |
| <daemon9> yah.. | |
| <_e|f_> d9: i take it by this yew aint interested? | |
| <_e|f_> :\ | |
| <daemon9> anyway, bak to pr0n. | |
| <W|ZaRD> anywayz.. op me d00d | |
| <w0zz> me too | |
| <w0zz> must have m0re pr0n | |
| *** Mode change "+m" on channel #supreme by daemon9 | |
| <daemon9> yes | |
| *** w0zz has left channel #supreme | |
| <daemon9> more pr0n | |
| <w0zz:#!r00t> werd | |
| <w0zz:#!r00t> that rooled | |
| <daemon9> mega-pr0n | |
| <W|ZaRD> porn | |
| <W|ZaRD> hehe | |
| <daemon9> kiddie-pr0n | |
| <W|ZaRD> op me plz | |
| <daemon9> wizard, you are fine the way you are. | |
| *** w0zz is now known as [w0zzz] | |
| *** daemon9 has left channel #supreme | |
| *** daemon9 is now known as r0ute | |
| <r0ute> hahaha | |
| <[w0zzz]> heh | |
| <r0ute> that was fun. | |
| <r0ute> good way to wake up from a nap | |
| ----<>---- | |
| Large Packet Attacks | |
| (AKA Ping of Death) | |
| --------------------------------- | |
| [ Introduction ] | |
| Recently, the Internet has seen a large surge in denial of service | |
| attacks. A denial of service attack in this case is simply an action of some | |
| kind that prevents the normal functionality of the network. It denies service. | |
| This trend began a few months back with TCP SYN flooding and continues with the | |
| "large packet attack". In comparison with SYN flooding, the large packet attack | |
| is a much more simple attack in both concept (explained below) and execution | |
| (the attack can be carried out by anyone with access to a Windows 95 machine). | |
| TCP SYN flooding is more complex in nature and does not exploit a flaw so much | |
| as it exploits an implementation weakness. | |
| The large packet attack is also much more devastating then TCP SYN | |
| flooding. It can quite simply cause a machine to crash, whereas SYN flooding | |
| may just deny access to mail or web services of a machine for the duration of | |
| the attack. For more information on TCP SYN flooding see Phrack 49, article 13. | |
| (NOTE: The large packet attack is somewhat misleadingly referred to as 'Ping of | |
| Death` because it is often delivered as a ping packet. Ping is a program that | |
| is used to test a machine for reachablity to see if it alive and accepting | |
| network requests. Ping also happens to be a convenient way of sending the | |
| large packet over to the target.) | |
| The large packet attack has caused no end of problems to countless | |
| machines across the Internet. Since its discovery, *dozens* of operating | |
| system kernels have been found vulnerable, along with many routers, terminal | |
| servers, X-terminals, printers, etc. Anything with a TCP/IP stack is in fact, | |
| potentially vulnerable. The effects of the attack range from mild to | |
| devastating. Some vulnerable machines will hang for a relatively short period | |
| time then recover, some hang indefinitely, others dump core (writing a huge | |
| file of current memory contents, often followed by a crash), some lose | |
| all network connectivity, many rebooted or simply gave up the ghost. | |
| [ Relevant IP Basics ] | |
| Contrary to popular belief, the problem has nothing to do with the | |
| `ping` program. The problem lies in the IP module. More specifically, | |
| the problem lies the in the fragmentation/reassembly portion of the IP module. | |
| This is portion of the IP protocol where the packets are broken into smaller | |
| pieces for transit, and also where they are reassembled for processing. An IP | |
| packet has a maximum size constrained by a 16-bit header field (a header is a | |
| portion of a packet that contains information about the packet, including | |
| where it came from and where it is going). The maximum size of an IP packet | |
| is 65,535 (2^16-1) bytes. The IP header itself is usually 20 bytes so this | |
| leaves us with 65,515 bytes to stuff our data into. The underlying link layer | |
| (the link layer is the network logically under IP, often ethernet) can seldom | |
| handle packets this large (ethernet for example, can only handle packets up to | |
| 1500 bytes in size). So, in order for the link layer to be able to digest a | |
| large packet, the IP module must fragment (break down into smaller pieces) | |
| each packet it sends to down to the link layer for transmission on the network. | |
| Each individual fragment is a portion of the original packet, with its own | |
| header containing information on exactly how the receiving end should put it | |
| back together. This putting the individual packets back together is called | |
| reassembly. When the receiving end has all of the fragments, it reassembles | |
| them into the original IP packet, and then processes it. | |
| [ The attack ] | |
| The large packet attack is quite simple in concept. A malicious user | |
| constructs a large packet and sends it off. If the destination host is | |
| vulnerable, something bad happens (see above). The problem lies in the | |
| reassembly of these large packets. Recall that we have 65,515 bytes of space | |
| in which to stuff data into. As it happens, a few misbehaved applications | |
| (and some specially crafted evil ones) will allow one to place slightly more | |
| data into the payload (say 65,520 bytes). This, along with a 20 byte IP | |
| header, violates the maximum packet size of 65,535 bytes. The IP module will | |
| then simply break this oversized packet into fragments and eschew them to | |
| their intended destination (target). The receiving host will queue all of the | |
| fragments until the last one arrives, then begin the process of reassembly. | |
| The problem will surface when the IP module finds that the packet is in | |
| fact larger than the maximum allowable size as an internal buffer is | |
| overflowed. This is where something bad happens (see above). | |
| [ Vulnerability Testing and Patching ] | |
| Testing to see if a network device is vulnerable is quite easy. | |
| Windows NT and Windows 95 will allow construction of these oversized | |
| packets without complaining. Simply type: `ping -l 65508 targethost`. In | |
| this case, we are delivering an oversized IP packet inside of a ping packet, | |
| which has a header size of 8 bytes. If you add up the totals, 20 bytes of IP | |
| header + 8 bytes of ping header + 65,508 bytes of data, you get a 65,536 byte | |
| IP packet. This is enough to cause affected systems to have problems. | |
| Defense is preventative. The only way to really be safe from this | |
| attack is to either ensure your system is patched, or unplug its network tap. | |
| There are patches available for just about every vulnerable system. For | |
| a copious list of vulnerable systems and patches, check out a 'Ping of Death' | |
| webpage near you. | |
| daemon9 | |
| Editor, Phrack Magazine | |
| (daemon9@netcom.com) | |
| --------------------------------------------------------------------------- | |
| To: route@onyx.infonexus.com | |
| From: xxxx xxxxxxxxxxx <xxxx@xxxxxxxxxx.com> | |
| Subject: Re: ? | |
| Status: RO | |
| Actually, hang on. I've looked your story up and down looking for ways to | |
| make it more interesting and I can't. I think it's actually just too | |
| technical for us and lacks a newsworthiness that was evident in the SYN | |
| article. I mean, you never tell us why we should care about this, and | |
| frankly, I don't know why we should. So, you're welcome to take another | |
| pass at it, otherwise, I'll give you the kill fee of $100. | |
| xxxx | |
| [ Too techinical? Any less techincal and I would have to make everything | |
| rhyme so people wouldn't fall asleep. ] | |
| --------------------------------------------------------------------------- | |
| ----<>---- | |
| Netware Insecurities | |
| Tonto | |
| [the rant] | |
| I realize that to most security professionals and | |
| system administrators who will see this magazine, | |
| the term "NetWare security" is a punchline. That | |
| unfortunately does not change the fact that many | |
| people in the field, myself included, must deal | |
| with it daily. Really, honestly, I do agree with | |
| you. Please don't write me to tell me about how | |
| futile it is. I already know. | |
| Since its release, not much security news has really | |
| surfaced surrounding Novell NetWare 4. A lot of the | |
| security flaws that were present in 3.1x were 'fixed' | |
| in 4.x since Novell pretty much redesigned the way | |
| the user/resource database worked, was referenced, | |
| and stored. Some flaws remained, although fixes for | |
| them are well-known, and easily applied. However, | |
| NetWare 4 came with its own batch of new security | |
| flaws, and Novell has done a poor job of addressing | |
| them, hoping that consumer-end ignorance and the | |
| client/server software's proprietary design will hide | |
| these holes. You'd figure they would know better by | |
| now. | |
| The ability to use a packet sniffer to snag RCONSOLE | |
| passwords still exists; NetWare 4 institutes client-end | |
| authentication to implement its auto-reconnect feature; | |
| the list goes on. Below are just a couple of examples | |
| of such bugs and how to deal with them. As new Novell | |
| products bring many existing LANs out onto the Internet, | |
| I think you will see more of this sort of thing coming | |
| to the surface. I hope that when it does, Novell decides | |
| to take a more responsible role in security support for | |
| its products. I'd hate for such a widely used product | |
| to become the next HP/UX. | |
| [the exploits] | |
| [BUG #1] | |
| This bug is known to affect NetWare 4.10. It's probably present in 4.01 | |
| and other versions that support Directory Services, but I haven't | |
| verified this. I'm only a CNA, so I tried to verify this bug by talking | |
| to a group of CNEs and nobody had heard of this, although there are | |
| apparently other bugs in previous versions of LOGIN.EXE. | |
| The bug is a combination of some weak code in LOGIN-4.12 | |
| (SYS:\LOGIN\LOGIN.EXE) and a default User object in NDS - the user template | |
| USER_TEMPLATE. LOGIN allows input fields to be passed directly, instead | |
| of filtered, if they are passed to LOGIN correctly -- by specifying an | |
| object's context explicitly (as opposed to implicitly by using CX) and | |
| putting the User object's name in quotes. | |
| F:\PUBLIC>LOGIN SVR1/"USER_TEMPLATE" | |
| For Server object SVR1 in an appropriate context, this would probably work | |
| and give a generic level of user access, perhaps to other volumes, | |
| programs, etc. That will vary depending on the setup of the server. | |
| The fix is simple. Load SYS:\PUBLIC\NWADMIN.EXE and disable the user | |
| template's login. But from now on, you will have to manually enable | |
| login for any new User objects created in your tree. | |
| [BUG #2] | |
| This isn't a bug as much as a failed attempt to add security to a DOS file | |
| system. But since Novell touts (and teaches) it as a file system security | |
| tool, it is worth addressing. | |
| NetWare comes with a tool called FLAG, which is supposed to be the NetWare | |
| equivalent of UNIX's chmod(), in that it controls file attributes for files | |
| on local and NetWare file systems. The problem lies in that Novell | |
| thought it would be neat to incorporate its tool into the world of DOS file | |
| attributes as well. So they made FLAG alter DOS file attributes | |
| automatically to correspond with the new attributes installed by FLAG. | |
| This would've been cool, except that DOS's ATTRIB.EXE can also be used to | |
| change the DOS-supported file attributes set by FLAG. (Archive, Read-only, | |
| Hidden, and System, respectively) And since ATTRIB doesn't reference NDS | |
| in any way, the problem is obvious; A file that was marked Read-only by | |
| its owner, using FLAG, could be compromised by a user other than its owner, | |
| with ATTRIB, and then altered or deleted. | |
| There isn't an easy fix for something that is this broken, so it is | |
| simply recommended that you use IRFs (carefully) to designate file rights | |
| on your server. | |
| [ 01-07-97 - Tont0 ] | |
| ----<>---- | |
| EOF | |