Dria

Summary : The transferFrom function is used to transfer tokens from one address to another. However, in this case, the from address is set to listing.buyer, which is an arbitrary address that can be controlled by an attacker.

Vulnerability Details : The Swan.purchase function in the Swan contract uses an arbitrary from address in the transferFrom function, allowing an attacker to manipulate the from address and potentially drain the funds of an unsuspecting victim.

What is the issue?

The issue is that the transferFrom function is called with an arbitrary from address, which is set to listing.buyer. This allows an attacker to manipulate the from address and transfer tokens from an unintended address.

How can an attacker exploit this vulnerability?

How can an attacker exploit this vulnerability?

An attacker can exploit this vulnerability by:

1. Creating a malicious listing: An attacker can create a malicious listing with a buyer address that is under their control.

2. Calling the purchase function: The attacker can call the purchase function, passing in the malicious listing.

3. Manipulating the from address: The attacker can manipulate the from address to transfer tokens from an unintended address.

4. Draining the funds of the victim: The attacker can drain the funds of the victim by transferring tokens from the unintended address.

Example Attack Scenario:

1. An attacker creates a malicious listing with a buyer address that is under their control.

2. The attacker calls the purchase function, passing in the malicious listing.

3. The transferFrom function is called with the arbitrary from address set to the attacker's controlled address.

4. The attacker manipulates the from address to transfer tokens from an unintended address, potentially draining the funds of an unsuspecting victim.

Prevention:

What are the consequences of this vulnerability?

The consequences of this vulnerability are severe, as an attacker can potentially drain the funds of an unsuspecting victim. This can result in significant financial losses for the victim and damage to the reputation of the Swan contract.

Impact : The consequences of this vulnerability are severe, as an attacker can potentially drain the funds of an unsuspecting victim. This can result in significant financial losses for the victim and damage to the reputation of the Swan contract.

The Swan.purchase function in the Swan contract uses an arbitrary from address in the transferFrom function, allowing an attacker to manipulate the from address and potentially drain the funds of an unsuspecting victim.

Proof of Concept Code : Here is a proof of concept code that demonstrates the vulnerability:

In this example, the Attacker contract creates a malicious listing and calls the purchase function on the Swan contract. The Swan contract then transfers tokens from the msg.sender address to the maliciousListing address. The Attacker contract then manipulates the from address to transfer tokens from the Swan contract to the Attacker contract.

This proof of concept code demonstrates the vulnerability and shows how an attacker can exploit it to drain the funds of an unsuspecting victim.

Tools Used : Slither

Recommendations : To prevent this type of attack, it is essential to:

1. Use a trusted address: Use a trusted address, such as msg.sender, as the from address in the transferFrom function.

2. Implement input validation: Implement input validation to ensure that the buyer address is valid and not under the control of an attacker.

3. Implement access control: Implement access control to ensure that only authorized addresses can call the purchase function.

To fix this vulnerability, the from address in the transferFrom function should be set to a trusted address, such as the msg.sender address. This ensures that the tokens are transferred from the intended address and prevents an attacker from manipulating the from address.

Code Fix:

By setting the from address to msg.sender, we ensure that the tokens are transferred from the intended address and prevent an attacker from manipulating the from address.