C

Craig Heffner

devttys0.com · Personal blog · on HN since 2010

Craig Heffner reverse engineers embedded devices and router firmware, publishing detailed write-ups on backdoors and vulnerabilities in D-Link and Linksys products.

What HN saysHN commenters cite it as evidence of poor router firmware quality, especially D-Link's backdoors and unpatched bugs, and as a reason routers can't be trusted to be secure.
38HN people shared it
16linked it in comments
31stories submitted
1.8Kstory points
10 years agolast shared
2010people per year2026

Most-shared posts

  1. 1
    From China, With Love
    5 people · 199 points · first shared 2013 · 60 comments on HN
  2. 2
    Reverse Engineering a D-Link Backdoor
    4 people · 196 points · first shared 2013 · 30 comments on HN
  3. 3
    Hacking the D-Link DIR-890L
    3 people · 76 points · first shared 2015 · 15 comments on HN
  4. 4
    Reverse Engineering Serial Ports
    3 people · 4 points · first shared 2012 · discussion on HN
  5. 5
    Embedded Device Hacking from /dev/ttys0
    3 people · 1 points · first shared 2012 · discussion on HN
  6. 6
  7. 7
    WRT120N fprintf Stack Overflow
    2 people · 189 points · first shared 2014 · 42 comments on HN
  8. 8
    Cracking Linksys “Encryption”
    2 people · 132 points · first shared 2014 · 46 comments on HN
  9. 9
    Reversing D-Link’s WPS Pin Algorithm
    2 people · 96 points · first shared 2014 · 24 comments on HN
  10. 10
    Jailbreaking a set top box with the remote
    2 people · 13 points · first shared 2012 · discussion on HN
  11. 11
    Hacking the DSP-W215, Again, Again, Again
    2 people · 11 points · first shared 2014 · 2 comments on HN
  12. 12
    Hacking the D-Link DSP-W215 Smart Plug
    2 people · 4 points · first shared 2014 · discussion on HN
  13. 13
    Reversing Belkin’s WPS Pin Algorithm
    2 people · 4 points · first shared 2015 · discussion on HN
  14. 14
    Differentiate Encryption From Compression Using Math
    2 people · 4 points · first shared 2013 · discussion on HN
  15. 15
    Breaking SSL on Embedded Devices
    2 people · 4 points · first shared 2010 · discussion on HN

What HN people wrote when they linked it

voltagex_ · 2016-06-22
I'll write one when I find something worthy of it. I've got stupidly high standards though. I've bought everything from wireless hard drives to $250 Wifi routers to $20 ethernet/3G bridges and the quality of the firmware is pretty garbage on all of them. I see brand new devices on kernel 2.4 and 2.6 with no upgrade plans in sight, and hacked up kernel trees that have no chance of building except on the developers' Red Hat 9 (!) workstations. http://www.devttys0.com/blog/ is another good place to follow. I guess it's more fun to write a negative article, not to mention it gets a lot more views.
rasz_pl · 2015-09-17
It is NOT by mistake. Dlink engineers are INCREDIBLY INCOMPETENT. Let me remind you this excellent piece: http://www.devttys0.com/2015/04/what-the-ridiculous-fuck-d-link/
ryanmcdonough · 2015-05-27
You don't. Lock it down as best you can: http://www.tomsguide.com/us/home-router-security,news-19245.html But as for the software being immune to vulnerabilities - no chance. Read http://www.devttys0.com/2015/04/hacking-the-d-link-dir-890l/ which lists huge security issues and then D-LINK putting out a patch which doesn't even fix what they said it did.
jonalmeida · 2014-01-22
Reminds me of the backdoor in D-Links routers: http://www.devttys0.com/2013/10/from-china-with-love/
ten7 · 2010-12-19
Great article. So what's the fix? What should the right approach have been? Let's see a solution! And yes, I read the blog post associated with it and didn't see a solution: http://www.devttys0.com/2010/12/breaking-ssl-on-embedded-devices/
klapinat0r · 2016-04-17
> What then struck me was the way he casually decided to hack a VPN He's intentionally vague, but given he mentions two routers and two vpn systems, it's highly probable that he's referring to one of the two routers (which is embedded, and has firmware). Furthermore, he refers to a website[1] which predominately deals with routers. > is it really so straightforward? Routers, yes[2], VPN daemons, not as much. [1]: http://www.devttys0.com/training/ - which can also contain a vpn daemon of course. [2]: https://github.com/darkarnium/secpub/tree/master/Multivendor/ncc2
gamed · 2015-01-09
This is often the case with WPS on home routers. Here's a blog post detailing the reversing of D-Links WPS PIN generation. http://www.devttys0.com/2014/10/reversing-d-links-wps-pin-algorithm/
throwaway2048 · 2014-04-10
I suspect this is going to cause a significant problem in the future with regaurds to all these embedded home routers that stopped receiving updates 6 months after release. Its essentially an unmonitored backdoor to 95% of networks on earth. http://www.devttys0.com/2013/10/reverse-engineering-a-d-link-backdoor/ http://arstechnica.com/security/2014/02/bizarre-attack-infects-linksys… Not to mention the similar situation with android phones. What a spectacular mess.
himal · 2014-02-02
Also there is a list of tools located at http://www.devttys0.com/tools/
w1ntermute · 2013-10-19
Off-topic: does anyone know what software was used to make graphics like http://www.devttys0.com/wp-content/uploads/2013/10/recvfrom.png ?
shabble · 2013-07-03
Not quite what you're talking about, but there was recently a couple of posts by the 'binwalk' author about differentiating encrypted vs compressed data (presumed header-less): http://www.devttys0.com/2013/06/differentiate-encryption-from-compress… http://www.devttys0.com/2013/06/encryption-vs-compression-part-2/
I hacked my Fritz!Box (yeah, a bad name for a german router) and I'm entirely sure that it has a backdoor integrated too. That's why I wiped and flashed it with an alternative image. That and the Telecom's Speedport router are the most popular routers by far in Germany. And both have backdoors, I know that other router manufacturers also integrate backdoors from a source who works at such a company. A friend can also verify the fact, because a different employee told him the same. Also it's public that the ISP can upgrade, modify, flash and disable features remotely. My friend's router has wifi, but their provider disabled it remotely within the firmware (it even has an antenna) and his ISP wants him to pay 5€/m to re-enable wifi. I really wonder why nobody complained about that earlier. Also the interesting thing here is that for a very long time, you weren't allowed to use a different router than the one provided by your ISP. Which enforced their surveillance monopoly. Here's an article about reverse engineering the backdoor in D-Link routers using IDA: http://www.devttys0.com/2013/10/reverse-engineering-a-d-link-backdoor/ PoC Available: http://pastebin.com/vbiG42VD

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