square

Square

We make selling simple for businesses of all sizes.

Serious about security

Our approach to security is designed to protect buyers and sellers. We monitor every transaction from swipe to payment, we continuously innovate in fraud prevention, and we protect businesses’ data like our business depends on it—because it does. We adhere to industry-leading standards to manage our network, secure our web and client applications, and set policies across our organization.

  • Severe: Any bug that might grant unauthorized access to confidential bug descriptions. Severe bugs have a minimum bounty of $2,500.
  • Interesting: Any bug that might otherwise potentially impact the security of our service. Interesting bugs have a minimum bounty of $300.

 
We are particularly interested in problems with Square’s payment flows. Confirmed vulnerabilities that directly affect our payments flows will receive a $500 minimum reward.

If you believe you have discovered a security vulnerability, please follow the guidelines below.

 

Disclosure procedures

Square recognizes the important contributions the security research community can make. We encourage coordinated reporting of security issues with our services. We take the security of our services very seriously and monitor their use for indications of a malicious attack. In order to allow us to identify legitimate security research as opposed to malicious attacks against our services, we promise not to bring legal action against researchers who:

  • Share with us the full details of any problem found.
  • Do not disclose the issue to others until we’ve had reasonable time to address it.
  • Do not intentionally harm the experience or usefulness of the service to others.
  • Never attempt to view, modify, or damage data belonging to others.
  • Do not attempt a denial-of-service attack.
  • Do not perform any research or testing in violation of law.

 

Attributes of a good report

  • Detailed steps on reproducing the bug. If valuable, please include any screenshots, links you clicked on, pages visited, etc.
  • Describe the versions of all relevant components of the attack (eg browser, OS, mobile app version).
  • Describe a concrete attack scenario. How will the problem impact Square or Square buyers/sellers? Put the problem into context.

 

Scope

We welcome you to report problems related to the following web domains:

 
Our Android and iOS mobile applications for Square Cash and Square Register are also in scope:

 

Keep in mind that:

 

Special CTF-style Flags!

Find the account

We've created an account with an email address of the form ftwr+[32 character flag]@squareup.com. Tell us how you found it, and you'll get a $1000 bounty. In case it helps, you can find the associated Square Market page here.

The SHA1 digest of the flag is: b9559723b3fd537e368fdc5c221eef72dc2e8adc.

Find the file

Find a file called hackerone-flag.txt with the contents of the form ftwr+[32 character flag]. Tell us how you found it, and you'll get a $1000 bounty.

The SHA1 digest of the flag is: 1fb27653e08cef9c6acdd520f2e9398ad3576549.

Computing the sha1

To make sure you know that you have found the right flag, we are publishing the digests of the flags by running echo [32 characters] | sha1sum. You can do the same on your terminal (you might need to install sha1sum or use an alternate method).
For example, if the value of the token were fb3f8fe63cc107c1977855c95633fb13 (it's not), then you would get:

~ echo -n fb3f8fe63cc107c1977855c95633fb13 | sha1sum
53aa4d47f93b76214834193baefb9c6e7d042c11  -

Rules

Some things to keep in mind when hunting for flags:

  • Only flags created by Square are eligible for the reward. There will be at most one reward per flag.
  • Only the first person to report a flag and methodology for discovery will be rewarded.
  • The flags are long enough that brute force won't work. You'll have to be more creative!

 

Ineligible reports

  • Issues related to software not under Square's control
  • Reports from automated tools or scans
  • Social engineering of Square staff or contractors
  • Any physical attempts against Square property or data centers
  • Logout CSRF
  • Presence of autocomplete attribute on web forms
  • Missing cookie flags on non-sensitive cookies
  • Missing http security headers (unless you deliver a proof of concept that leverages their absence)
  • Clickjacking on widgets intended to be embedded in other pages
  • Reports of insecure SSL/TLS ciphers (unless you have a working proof of concept, and not just a report from a scanner)
  • An oracle that discloses whether a given username, email address, or phone number is associated with an actual account. (However, please do submit anything that allows you to recover usernames en masse.)
  • Using spoofed emails for phishing

Domains

  • squareup.com
  • square.com
  • cash.me
Now
Square resolved a report that was submitted by vakzz.
13 days ago
Square rewarded vakzz with a $300 bounty.
13 days ago
Square resolved a report that was submitted by linkks.
18 days ago
Square rewarded linkks with a $300 bounty.
18 days ago
Square resolved a report that was submitted by phobusenko.
18 days ago
Square rewarded phobusenko with a $500 bounty.
18 days ago
Square resolved a report that was submitted by prayas.
19 days ago
Square resolved a report that was submitted by zombiehelp54.
24 days ago
Square rewarded zombiehelp54 with a $500 bounty.
24 days ago
Square resolved a report that was submitted by apo143u.
25 days ago
Square rewarded apo143u with a $300 bounty.
25 days ago
Square resolved a report that was submitted by drosera.
25 days ago
Square rewarded drosera with a $300 bounty.
25 days ago
Square rewarded ananthapadmaraman with a $500 bounty.
About 1 month ago
Square rewarded balvinder with a $500 bounty.
About 1 month ago
Square resolved a report that was submitted by balvinder.
About 1 month ago
Square rewarded harisec with a $750 bounty.
About 2 months ago
Square resolved a report that was submitted by harisec.
About 2 months ago
Square resolved a report that was submitted by ananthapadmaraman.
About 2 months ago
Square resolved a report that was submitted by ananthapadmaraman.
About 2 months ago
Square rewarded ananthapadmaraman with a $300 bounty.
About 2 months ago
Square resolved a report that was submitted by skelor.
About 2 months ago
Square rewarded elamaran619 with a $500 bounty.
About 2 months ago
Square resolved a report that was submitted by elamaran619.
About 2 months ago
Square resolved a report that was submitted by meals.
About 2 months ago
Square rewarded kyprizel with a $500 bounty.
2 months ago
Square resolved a report that was submitted by kyprizel.
2 months ago
Square rewarded bastianwelfrid with a $300 bounty.
2 months ago
Square resolved a report that was submitted by bastianwelfrid.
2 months ago
Square resolved a report that was submitted by linkks.
3 months ago
Square rewarded linkks with a $300 bounty.
3 months ago
Square rewarded ananthapadmaraman with a $500 bounty.
3 months ago
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