Lack of limits for length parameters

Oct 13, 2025 by magicalceylontours.com 140 views

Cheesy Raisin Dachshund - Anyone can pass any length to some Tally imports to inflate memory, induce OOM, and crash validators

Summary

A Tally program can use Tally imports like secp256k1_verify and set its message_length, signature_length, and public_key_length to max::u32 and bloat memory usage by 12GB. This can lead to a denial-of-service (DoS) attack, causing chain halts due to Out-of-Memory (OOM) errors.

Root Cause

There are two root causes for this issue:

Lack of limits for length parameters: The message_length, signature_length, and public_key_length parameters in the secp256k1_verify import have no limits, allowing an attacker to set them to max::u32 and cause memory inflation.
Low gas costs: The gas cost for calling secp256k1_verify with max lengths is only ~4.3e13 SEDA tokens, which is negligible compared to the cost of bloating all SEDA Chain validators' memory by 12GB.

Internal Pre-conditions

None

External Pre-conditions

None

Attack Path

Create a malicious WASM program: The attacker creates a WASM program that calls the secp256k1_verify import with max::u32 values for message_length, signature_length, and public_key_length.
Compile and deploy the WASM program: The attacker compiles the WASM program and deploys the binary via StoreOracleProgram().
Post a Data Request: The attacker posts a Data Request that will execute their earlier deployed Tally Program.
Process the Data Request: Once the Data Request is for tallying, it will be processed in the Tally module's EndBlock().
Execute the Attacker's Tally Program: When executing the Attacker's Tally Program, the validator node's memory usage will inflate by ~12GB, causing a chain halt due to OOM errors.

Impact

Crashing multiple validators due to Out-of-Memory can cause chain halts, leading to a denial-of-service (DoS) attack.

PoC

The example WASM program that exploits the issue in secp256k1_verify is shown below:

#[link(wasm_import_module = "seda_v1")]
extern "C" {
    pub fn secp256k1_verify(
        message: *const u8,
        message_length: i64,
        signature: *const u8,
        signature_length: i32,
        public_key: *const u8,
        public_key_length: i32,
    ) -> u8;
}

fn main() {
    let result = vec![1, 2, 3];
    unsafe {
        secp256k1_verify(
            result.as_ptr(), 
            u32::MAX as i64,
            result.as_ptr(),
            -1i32,
            result.as_ptr(), 
            -1i32,
        );
    }
}

Mitigation

To mitigate this issue, consider the following:

Limit length parameters: Limit the message_length, signature_length, and public_key_length parameters in all Tally imports to prevent memory inflation.
Increase gas costs: Increase the gas costs for calling secp256k1_verify with max lengths to make it more expensive for attackers to launch a DoS attack.

By implementing these mitigations, you can prevent attackers from exploiting this vulnerability and causing chain halts due to Out-of-Memory errors.

Calculation for memory use

If max::u32 is used as length for all, the calculation for the memory use is as follows:

message_length:     4,294,967,295 bytes
signature_length:   4,294,967,295 bytes
public_key_length:  4,294,967,295 bytes
                   ---------------
Total:            12,884,901,885 bytes

Converting to GB:
12,884,901,885 / 1,073,741,824 ≈ 12 GB

Calculation for gas cost

The gas cost for calling secp256k1_verify with max lengths is calculated as follows:

gas_cost = 1e7 + 1e7 + (1e4 * bytes_length)
bytes_length = maxU32 ~= 4.3e9
gas_cost = 1e7 + 1e7 + (1e4 * ~4.3e9)
gas_cost = ~4.3e13   // The gas cost is much less than 1e18 SEDA tokens

Note that the issue also exists in keccak256 and execution_result but in lesser degrees.
Cheesy Raisin Dachshund - Anyone can pass any length to some Tally imports to inflate memory, induce OOM, and crash validators

Q&A

Q: What is the Cheesy Raisin Dachshund vulnerability?

A: The Cheesy Raisin Dachshund vulnerability is a denial-of-service (DoS) attack that can be launched by passing large values to the message_length, signature_length, and public_key_length parameters in the secp256k1_verify import. This can cause memory inflation and lead to a chain halt due to Out-of-Memory (OOM) errors.

Q: What are the root causes of the Cheesy Raisin Dachshund vulnerability?

A: There are two root causes of the Cheesy Raisin Dachshund vulnerability:

Lack of limits for length parameters: The message_length, signature_length, and public_key_length parameters in the secp256k1_verify import have no limits, allowing an attacker to set them to max::u32 and cause memory inflation.
Low gas costs: The gas cost for calling secp256k1_verify with max lengths is only ~4.3e13 SEDA tokens, which is negligible compared to the cost of bloating all SEDA Chain validators' memory by 12GB.

Q: How can an attacker exploit the Cheesy Raisin Dachshund vulnerability?

A: An attacker can exploit the Cheesy Raisin Dachshund vulnerability by:

Creating a malicious WASM program: The attacker creates a WASM program that calls the secp256k1_verify import with max::u32 values for message_length, signature_length, and public_key_length.
Compiling and deploying the WASM program: The attacker compiles the WASM program and deploys the binary via StoreOracleProgram().
Posting a Data Request: The attacker posts a Data Request that will execute their earlier deployed Tally Program.
Processing the Data Request: Once the Data Request is for tallying, it will be processed in the Tally module's EndBlock().
Executing the Attacker's Tally Program: When executing the Attacker's Tally Program, the validator node's memory usage will inflate by ~12GB, causing a chain halt due to OOM errors.

Q: What is the impact of the Cheesy Raisin Dachshund vulnerability?

A: The impact of the Cheesy Raisin Dachshund vulnerability is a chain halt due to Out-of-Memory (OOM) errors, which can be caused by an attacker launching a denial-of-service (DoS) attack.

Q: How can the Cheesy Raisin Dachshund vulnerability be mitigated?

A: The Cheesy Raisin Dachshund vulnerability can be mitigated by:

Limiting length parameters: Limit the message_length, signature_length, and public_key_length parameters in all Tally imports to prevent memory inflation.
Increasing gas costs: Increase the gas costs for calling secp256k1_verify with max lengths to make it more expensive for attackers to launch a DoS attack.

Q: What is the calculation for memory use if max::u32 is used as length for all?

A: The calculation for memory use if max::u32 is used as length for all is as follows:

message_length:     4,294,967,295 bytes
signature_length:   4,294,967,295 bytes
public_key_length:  4,294,967,295 bytes
                   ---------------
Total:            12,884,901,885 bytes

Converting to GB:
12,884,901,885 / 1,073,741,824 ≈ 12 GB

Q: What is the calculation for gas cost if max::u32 is used as length for all?

A: The gas cost for calling secp256k1_verify with max lengths is calculated as follows:

gas_cost = 1e7 + 1e7 + (1e4 * bytes_length)
bytes_length = maxU32 ~= 4.3e9
gas_cost = 1e7 + 1e7 + (1e4 * ~4.3e9)
gas_cost = ~4.3e13   // The gas cost is much less than 1e18 SEDA tokens

Note that the issue also exists in keccak256 and execution_result but in lesser degrees.