Paymenter is a free and open-source webshop solution for management of hosting services. Prior to 1.5.7, app/Livewire/Services/Upgrade.php::doUpgrade() relies on Service::upgradable to check for a pending service upgrade and later executes $credit->increment('amount', abs($price)) without DB::transaction or lockForUpdate() spanning those operations. An authenticated customer with an active downgradable service can submit concurrent downgrade requests that each observe no pending upgrade, create separate upgrade records, and increment the same account credit balance, producing multiple spendable refunds for one downgrade.
This issue is fixed in version 1.5.7.
Attack Parameters
Attack Vector
Network
Can be exploited remotely
Attack Complexity
Low
Easy to exploit
Privileges Required
Low
Basic privileges needed
User Interaction
None
No user interaction needed
Impact Assessment
Confidentiality
None
No data leak
Integrity
High
Complete data modification
Availability
None
No disruption
CVSS Vector v3.1
Weakness Type (CWE)
References 3
https://github.com/Paymenter/Paymenter/commit/a42e7f8bafce054ad70de3a2c2ac94d13…
security-advisories@github.com
https://github.com/Paymenter/Paymenter/releases/tag/v1.5.7
security-advisories@github.com
https://github.com/Paymenter/Paymenter/security/advisories/GHSA-5gmm-hjfj-8ff7
security-advisories@github.com