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552,704 coordinated disclosures
355,146 fixed vulnerabilities
831 bug bounties with 1,611 websites
17,184 researchers, 1151 honor badges

Leon | Security Researcher Profile


Security researcher Leon has already helped fix 248 vulnerabilities.



Researcher reputation:  360

Real name:
Aldo Moreno

About me:
Cybersecurity enthusiast.
Bug bounty hunter.

How to contact me:
English or Spanish communication.

[email protected]

If you want to pentest your website, contact me.

Alternative Contacts:
[email protected]

Experience in Application Security
1-3 years

Award / Bug Bounty I prefer:
This is only if you want to reward me.
Paypal, Transferwise, BTC, gifts.

Paypal: [email protected]
Transferwise: [email protected]
BTC: 33x6BpPjBiR7g5UeefGQQuZLW2BVAd3aQV

Halls of Fame:
BBC
Dell
Papercut
PejaDesign
Tu-Chemnitz
Studis-Online
Telefonica Germany

Follow me on:
Twitter

Recommendations and Acknowledgements

    29 March, 2019
     Downnotify Marijn Otte from DownNotifier.com:
Aldo found a big security issue in our application, using a creative way to exploit it.
    21 February, 2020
     kevinBaseCom Kevin from Online Commerce Ltd:
Thanks for finding and alerting about an XSS issue with our newsletter.
    10 February, 2020
     SecuriteInfoCom Arnaud Jacques from SecuriteInfo.com:
Very good pentester.
Thank you Aldo !
    12 September, 2019
     phdev6 ph-dev from Peter Hahn:
Leon found a XSS bug on our site. Thanks a lot!
    23 April, 2019
     itsecop itsecop :
Thanks Geek_Pwn, for pointed out XSS vulnerabilities on our website!
Your input was very much appreciated!
    17 February, 2019
     JimM97459222 Jim from GH:
Thank you for pointing out the XSS vulnerability in our site. We appreciate your work and quick response. Thank you!!
    19 December, 2018
     HIGHFLYERS_WA Tom from WADC:
Thanks a lot for making our webserver more secure! Thums up!
    10 July, 2018
     nietofarias Ignacio Nieto from Despegar:
Thanks Aldo for reporting us some XSS vulnerabilities! It was very helpful!
    25 June, 2018
     TucWebmaster Frank Richter from TU Chemnitz:
Geek_Pwn discovered XSS bugs in my site. Thanks for reporting them to us and checking our fixes, your work is appreciated!
    7 June, 2018
     uriblackman Uri from GIDEON:
Thanks Geek_Pwn for finding and alerting us to the XSS bug.

Shows the first 10 recommendations. See all.

Please login via Twitter to add a recommendation

Honor Badges


Number of Secured Websites

10+ Websites
50+ Websites
500+ Websites
WEB SECURITY VETERAN
1000+ Websites

Advanced Security Research

WAF Bypasser
CSRF Master
30+ Reports
AppSec Logic Master
30+ Reports
Fastest Fix
Fix in 24 hours

Outstanding Achievements

Secured OBB
OBB Advocate
Improved OBB

Commitment to Remediate and Patch

Patch Master
55% Patched
Patch Guru
65% Patched
Patch Lord
75% Patched

Recommendations and Recognition

REPUTABLE
10+ Recommends
FAMOUS
25+ Recommends
GLOBALLY TRUSTED
50+ Recommends

Distinguished Blog Author

1 Post
3 Posts
5+ Posts

Research Statistics



Total reports:369
Total reports on VIP sites:40
Total patched vulnerabilities:248
Total vulnerabilities on Hold (Open Bug Bounty):12
Recommendations received:16
Active since:20.09.2017

Open Bug Bounty Certificate



18.09.2019  SSRF | Reading Local Files from DownNotifier server

Hello guys, this is my first write-up and I would like to share it with the bug bounty community, it’s a SSRF I found some months ago.

DownNotifier is an online tool to monitor a website downtime. This tool sends an alert to registered email and sms when the website is down.

DownNotifier has a BBP on Openbugbounty, so I decided to take a look on https://www.downnotifier.com. When I browsed to the website, I noticed a text field for URL and SSRF vulnerability quickly came to mind.


Reported Vulnerabilities

All Submissions VIP SubmissionsFeatured Submissions

Domain Reported Status Type
22.07.2020
On Hold
Cross Site Scripting
21.07.2020
On Hold
Cross Site Scripting
10.07.2020
On Hold
Cross Site Scripting
09.07.2020
On Hold
Cross Site Scripting
08.07.2020
On Hold
Cross Site Scripting
07.07.2020
On Hold
Cross Site Scripting
06.07.2020
On Hold
Cross Site Scripting
05.07.2020
patched
Cross Site Scripting
04.07.2020
On Hold
Cross Site Scripting
04.07.2020
On Hold
Cross Site Scripting
18.06.2020
On Hold
Cross Site Scripting
11.06.2020
On Hold
Improper Access Control 
10.06.2020
On Hold
Cross Site Scripting
10.06.2020
patched
Cross Site Scripting
20.02.2020
patched
Cross Site Scripting
16.02.2020
patched
Cross Site Scripting
10.02.2020
patched
Cross Site Scripting
29.01.2020
patched
Cross Site Scripting
21.01.2020
unpatched
Cross Site Scripting
01.12.2019
patched
Cross Site Scripting

  Latest Patched

 04.08.2020 care2.com
 03.08.2020 bankaustria.at
 03.08.2020 uscellular.com
 03.08.2020 avaya.com
 03.08.2020 rackspace.com
 03.08.2020 netcracker.com
 03.08.2020 lightreading.com
 03.08.2020 safer-networking.org
 03.08.2020 bullguard.com
 03.08.2020 cisco.com

  Latest Blog Posts

24.06.2020 by Gkexamquiz
How to Find Contacts To Report Bugs & Security Vulnerabilities | Bug Bounty Tutorials 2020
24.06.2020 by 0xcrypto
Improper Access Control - Generic: Unrestricted access to any "connected pack" on docs in coda.io
04.04.2020 by Rando02355205
(Alibaba) message.alibaba.com [IDOR] - [Bug Bounty]
12.03.2020 by Rando02355205
(Paypal) www.paypal.com [CSP High Level] - [XSS Reflected] - [Bug Bounty] - [Write Up]
08.03.2020 by CybeReports
JDECO.net XSS Vulnerability| CybeReports

  Recent Recommendations

    3 August, 2020
     Robert_CMI:
Thank you for reporting the vulnerability on our website, we very much appreciate your quick response and good description of the issue.
    1 August, 2020
     aboros:
Thank you for finding several issues on our site
    30 July, 2020
     HoutVasthouden:
Thank you Gaurav for helping us making our website a safer place! You reported a XSS vulnerability on one of our webforms, you gave us very clear information on the issue, so that we were able to fix the bug.
Keep up the good work!
    30 July, 2020
     h_ono:
Great work, thanks for finding a bug and kindly reporting it.
    30 July, 2020
     h_ono:
Great work, thanks for finding a bug and kindly reporting it.