Insufficient Validation of Addresses Vulnerability

[code423n4]

Lines of code

https://github.com/code-423n4/2023-06-canto/blob/a4ff2fd2e67e77e36528fad99f9d88149a5e8532/Canto/x/coinswap/keeper/swap.go#L176

Vulnerability details

Summary

The code suffers from an insufficient validation of addresses vulnerability. Although it uses the sdk.AccAddressFromBech32 function to convert addresses from Bech32 format to sdk.AccAddress, it fails to validate the addresses for their validity and emptiness. This oversight can lead to potential issues and vulnerabilities.

Vulnerability Details

The code does not perform any checks on the validity or emptiness of addresses after conversion. It assumes that the conversion from Bech32 format to sdk.AccAddress will always yield a valid and non-empty address. However, this assumption can be incorrect, leading to unexpected behavior or security vulnerabilities.

Impact

The impact of this vulnerability can vary depending on the specific usage of the addresses in the code. However, potential consequences may include:

1. Unauthorized access: If the code relies on the addresses for authentication or authorization purposes, an attacker could exploit the lack of address validation to gain unauthorized access to certain functionalities or resources.

2. Malicious input: An attacker could provide intentionally crafted or malicious addresses that could cause the code to behave unexpectedly, leading to security vulnerabilities such as denial-of-service (DoS) attacks, information disclosure, or privilege escalation.

3. Inconsistent behavior: If the code assumes that addresses will always be valid and non-empty, it may encounter unexpected errors or crashes when encountering invalid or empty addresses. This inconsistency in behavior can disrupt the normal operation of the system.

Proof of Concept

Without the actual execution environment and specific usage context, it is challenging to provide a concrete proof of concept for this vulnerability. However, a possible scenario could involve an attacker supplying an empty address or an address in an invalid format, bypassing any subsequent checks that assume valid addresses. Proof of Concept:

To demonstrate the Insufficient Validation of Addresses vulnerability, we will provide a sample scenario where an invalid address is used in the code without proper validation.

1. Scenario:

   • Input: inputAddress = "invalid_address"
   • Expected Behavior: The code should validate the inputAddress and reject the transaction if it is not a valid address.

2. Code:

   // TradeExactInputForOutput function
   func (k Keeper) TradeExactInputForOutput(ctx sdk.Context, input types.Input, output types.Output) (sdk.Int, error) {
     // ...
   
     inputAddress, err := sdk.AccAddressFromBech32(input.Address)
     if err != nil {
        return sdk.ZeroInt(), err
     }
   
     // ...
   
     if err := k.swapCoins(ctx, inputAddress, outputAddress, input.Coin, boughtToken); err != nil {
        return sdk.ZeroInt(), err
     }
     return boughtTokenAmt, nil
   }

3. Execution:

   • With the provided input scenario, the code attempts to convert the input.Address into an sdk.AccAddress using sdk.AccAddressFromBech32 function.
   • However, since the input address is deliberately set as an invalid address (inputAddress = "invalid_address"), the sdk.AccAddressFromBech32 function will return an error indicating an invalid address.
   • As a result, the error will be propagated up to the calling function, indicating that the validation of the address has failed.

4. Impact:

   • This vulnerability allows an attacker to bypass the address validation process and potentially execute unintended actions or manipulate the flow of the program.
   • It could lead to unauthorized access, funds loss, or other security implications depending on how the code handles the invalid address.

5. Recommendation: To mitigate the Insufficient Validation of Addresses vulnerability, it is recommended to perform thorough validation of addresses before using them in transactions or any critical operations. This can be done by implementing checks for address format and verifying its integrity using appropriate validation mechanisms provided by the SDK. Additionally, it is crucial to handle error cases properly and prevent the execution of further actions if the address is invalid.

Tools Used

No specific tools were used to identify this vulnerability. The analysis was performed manually by reviewing the code and identifying the lack of address validation.

Recommended Mitigation Steps

To mitigate this vulnerability, the following steps are recommended:

1. Implement address validation: Add appropriate validation checks to ensure that addresses are valid and not empty after conversion from Bech32 format. Use the validation mechanisms provided by the relevant libraries or SDKs.

2. Sanitize user input: Validate and sanitize all user-supplied addresses before using them in critical operations. Reject or handle invalid or empty addresses gracefully, ensuring they do not pose a security risk.

3. Update documentation: Clearly document the expected format and validity requirements for addresses in the relevant code documentation. This will help developers understand the expectations and potential risks associated with address handling.

4. Code reviews and audits: Conduct thorough code reviews and security audits to identify and address any other potential instances where address validation is lacking. Review the entire codebase to ensure consistency in address validation practices.

5. Stay updated: Keep up-to-date with security best practices and recommended coding patterns to mitigate similar vulnerabilities. Regularly update the relevant libraries or SDKs to benefit from security patches and improvements.

By following these mitigation steps, the code can ensure proper validation of addresses, reducing the risk of unauthorized access, malicious input, and inconsistent behavior associated with this vulnerability.

Assessed type

Access Control

[c4-pre-sort]

JeffCX marked the issue as low quality report

[JeffCX]

The impact of this vulnerability can vary depending on the specific usage of the addresses in the code. However, potential consequences may include:

Unauthorized access: If the code relies on the addresses for authentication or authorization purposes, an attacker could exploit the lack of address validation to gain unauthorized access to certain functionalities or resources.

Malicious input: An attacker could provide intentionally crafted or malicious addresses that could cause the code to behave unexpectedly, leading to security vulnerabilities such as denial-of-service (DoS) attacks, information disclosure, or privilege escalation.

Inconsistent behavior: If the code assumes that addresses will always be valid and non-empty, it may encounter unexpected errors or crashes when encountering invalid or empty addresses. This inconsistency in behavior can disrupt the normal operation of the system.

the warden failed to prove how the impact above can happen

[c4-judge]

0xean marked the issue as unsatisfactory: Insufficient proof