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Cosmos SDK - Story

Prepared by:

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HALBORN

Last Updated 12/12/2024

Date of Engagement by: October 29th, 2024 - November 12th, 2024

Summary

100% of all REPORTED Findings have been addressed

All findings

2

Critical

0

High

1

Medium

0

Low

1

Informational

0

Table of Contents

1. Introduction

Story engaged Halborn to conduct a security assessment on their Cosmos SDK, beginning on October 29, 2024, and ending on October 15, 2024. The security assessment was scoped to cover their cosmos-sdk GitHub repository, located at https://github.com/piplabs/cosmos-sdk/tree/ with commit ID 3d7ade1.

2. Assessment Summary

The team at Halborn was provided two weeks for the engagement and assigned one full-time security engineer to assess the security of the Cosmos project. The security engineer is a blockchain and smart-contract security expert with advanced penetration testing, smart-contract hacking, and deep knowledge of multiple blockchain protocols.

The purpose of this assessment is to:

    • Ensure that the Golang components operate as intended.

    • Identify potential security issues.

    • Identify lack of best practices within the codebase.

    • Identify systematic risks that may pose a threat in future releases.


In summary, Halborn identified some improvements to reduce the likelihood and impact of risks, which should be addressed by the Story team. The main ones were the following: 

    • Changed UnbondingIDKey to a different key to not overlap with other keys, which would allow storage corruption in certain situations.

    • Changed the duration types to the correct ones, as they did not matched the specs.

3. Test Approach and Methodology

Halborn performed a combination of manual and automated security testing to balance efficiency, timeliness, practicality, and accuracy in regard to the scope of the custom modules. While manual testing is recommended to uncover flaws in logic, process, and implementation; automated testing techniques help enhance coverage of structures and can quickly identify items that do not follow security best practices. The following phases and associated tools were used throughout the term of the assessment :

    • Research into architecture and purpose.

    • Static Analysis of security for scoped repository, and imported functions. (e.g., staticcheck, gosec...)

    • Manual Assessment for discovering security vulnerabilities on the codebase.

    • Ensuring the correctness of the codebase.

    • Dynamic Analysis of files and modules in scope.

4. RISK METHODOLOGY

Every vulnerability and issue observed by Halborn is ranked based on two sets of Metrics and a Severity Coefficient. This system is inspired by the industry standard Common Vulnerability Scoring System.
The two Metric sets are: Exploitability and Impact. Exploitability captures the ease and technical means by which vulnerabilities can be exploited and Impact describes the consequences of a successful exploit.
The Severity Coefficients is designed to further refine the accuracy of the ranking with two factors: Reversibility and Scope. These capture the impact of the vulnerability on the environment as well as the number of users and smart contracts affected.
The final score is a value between 0-10 rounded up to 1 decimal place and 10 corresponding to the highest security risk. This provides an objective and accurate rating of the severity of security vulnerabilities in smart contracts.
The system is designed to assist in identifying and prioritizing vulnerabilities based on their level of risk to address the most critical issues in a timely manner.

4.1 EXPLOITABILITY

Attack Origin (AO):
Captures whether the attack requires compromising a specific account.
Attack Cost (AC):
Captures the cost of exploiting the vulnerability incurred by the attacker relative to sending a single transaction on the relevant blockchain. Includes but is not limited to financial and computational cost.
Attack Complexity (AX):
Describes the conditions beyond the attacker’s control that must exist in order to exploit the vulnerability. Includes but is not limited to macro situation, available third-party liquidity and regulatory challenges.
Metrics:
EXPLOITABILIY METRIC (mem_e)METRIC VALUENUMERICAL VALUE
Attack Origin (AO)Arbitrary (AO:A)
Specific (AO:S)		1
0.2
Attack Cost (AC)Low (AC:L)
Medium (AC:M)
High (AC:H)		1
0.67
0.33
Attack Complexity (AX)Low (AX:L)
Medium (AX:M)
High (AX:H)		1
0.67
0.33
Exploitability EE is calculated using the following formula:

E=∏meE = \prod m_e

4.2 IMPACT

Confidentiality (C):
Measures the impact to the confidentiality of the information resources managed by the contract due to a successfully exploited vulnerability. Confidentiality refers to limiting access to authorized users only.
Integrity (I):
Measures the impact to integrity of a successfully exploited vulnerability. Integrity refers to the trustworthiness and veracity of data stored and/or processed on-chain. Integrity impact directly affecting Deposit or Yield records is excluded.
Availability (A):
Measures the impact to the availability of the impacted component resulting from a successfully exploited vulnerability. This metric refers to smart contract features and functionality, not state. Availability impact directly affecting Deposit or Yield is excluded.
Deposit (D):
Measures the impact to the deposits made to the contract by either users or owners.
Yield (Y):
Measures the impact to the yield generated by the contract for either users or owners.
Metrics:
IMPACT METRIC (mIm_I)METRIC VALUENUMERICAL VALUE
Confidentiality (C)None (I:N)
Low (I:L)
Medium (I:M)
High (I:H)
Critical (I:C)		0
0.25
0.5
0.75
1
Integrity (I)None (I:N)
Low (I:L)
Medium (I:M)
High (I:H)
Critical (I:C)		0
0.25
0.5
0.75
1
Availability (A)None (A:N)
Low (A:L)
Medium (A:M)
High (A:H)
Critical (A:C)		0
0.25
0.5
0.75
1
Deposit (D)None (D:N)
Low (D:L)
Medium (D:M)
High (D:H)
Critical (D:C)		0
0.25
0.5
0.75
1
Yield (Y)None (Y:N)
Low (Y:L)
Medium (Y:M)
High (Y:H)
Critical (Y:C)		0
0.25
0.5
0.75
1
Impact II is calculated using the following formula:

I=max(mI)+∑mI−max(mI)4I = max(m_I) + \frac{\sum{m_I} - max(m_I)}{4}

4.3 SEVERITY COEFFICIENT

Reversibility (R):
Describes the share of the exploited vulnerability effects that can be reversed. For upgradeable contracts, assume the contract private key is available.
Scope (S):
Captures whether a vulnerability in one vulnerable contract impacts resources in other contracts.
Metrics:
SEVERITY COEFFICIENT (CC)COEFFICIENT VALUENUMERICAL VALUE
Reversibility (rr)None (R:N)
Partial (R:P)
Full (R:F)		1
0.5
0.25
Scope (ss)Changed (S:C)
Unchanged (S:U)		1.25
1
Severity Coefficient CC is obtained by the following product:

C=rsC = rs

The Vulnerability Severity Score SS is obtained by:

S=min(10,EIC∗10)S = min(10, EIC * 10)

The score is rounded up to 1 decimal places.
SeverityScore Value Range
Critical9 - 10
High7 - 8.9
Medium4.5 - 6.9
Low2 - 4.4
Informational0 - 1.9

5. SCOPE

Files and Repository
(a) Repository: cosmos-sdk
(b) Assessed Commit ID: c553dc6
(c) Items in scope:
  • x/auth/ante/ante.go
  • x/auth/ante/ante_test.go
  • x/auth/ante/basic.go
↓ Expand ↓
Out-of-Scope: Third party dependencies and economic attacks.
Remediation Commit ID:
Out-of-Scope: New features/implementations after the remediation commit IDs.

6. Assessment Summary & Findings Overview

Critical

0

High

1

Medium

0

Low

1

Informational

0

Security analysisRisk levelRemediation Date
Key typo may allow store corruptionHighSolved - 11/27/2024
Incorrect default period durationLowSolved - 12/09/2024

7. Findings & Tech Details

7.1 Key typo may allow store corruption

// High

Description

There are two keys with the same value. As they are used as the prefix to retrieve the values under the Cosmos store, then it is possible to corrupt each other by being used on completely different parts of the codebase, as they would be querying the same key underneath.


The keys for the store prefixes are defined as follows:


https://github.com/piplabs/cosmos-sdk/blob/c553dc6734da1d49fcde55efd825d84998051dd7/x/staking/types/keys.go#L28C1-L60C2

var (
	// Keys for store prefixes
	// Last* values are constant during a block.
	LastValidatorPowerKey = []byte{0x11} // prefix for each key to a validator index, for bonded validators
	LastTotalPowerKey     = []byte{0x12} // prefix for the total power

	ValidatorsKey             = []byte{0x21} // prefix for each key to a validator
	ValidatorsByConsAddrKey   = []byte{0x22} // prefix for each key to a validator index, by pubkey
	ValidatorsByPowerIndexKey = []byte{0x23} // prefix for each key to a validator index, sorted by power

	DelegationKey                    = []byte{0x31} // key for a delegation
	UnbondingDelegationKey           = []byte{0x32} // key for an unbonding-delegation
	UnbondingDelegationByValIndexKey = []byte{0x33} // prefix for each key for an unbonding-delegation, by validator operator
	RedelegationKey                  = []byte{0x34} // key for a redelegation
	RedelegationByValSrcIndexKey     = []byte{0x35} // prefix for each key for an redelegation, by source validator operator
	RedelegationByValDstIndexKey     = []byte{0x36} // prefix for each key for an redelegation, by destination validator operator
	PeriodDelegationKey              = []byte{0x37} // key for a period delegation

	UnbondingIDKey    = []byte{0x37} // key for the counter for the incrementing id for UnbondingOperations
	UnbondingIndexKey = []byte{0x38} // prefix for an index for looking up unbonding operations by their IDs
	UnbondingTypeKey  = []byte{0x39} // prefix for an index containing the type of unbonding operations

	UnbondingQueueKey    = []byte{0x41} // prefix for the timestamps in unbonding queue
	RedelegationQueueKey = []byte{0x42} // prefix for the timestamps in redelegations queue
	ValidatorQueueKey    = []byte{0x43} // prefix for the timestamps in validator queue

	HistoricalInfoKey   = []byte{0x50} // prefix for the historical info
	ValidatorUpdatesKey = []byte{0x61} // prefix for the end block validator updates key

	ParamsKey = []byte{0x51} // prefix for parameters for module x/staking

	DelegationByValIndexKey = []byte{0x71} // key for delegations by a validator
)

However, in the case of PeriodDelegationKey and UnbondingIDKey keys:


https://github.com/piplabs/cosmos-sdk/blob/c553dc6734da1d49fcde55efd825d84998051dd7/x/staking/types/keys.go#L44C1-L46C105

	PeriodDelegationKey              = []byte{0x37} // key for a period delegation

	UnbondingIDKey    = []byte{0x37} // key for the counter for the incrementing id for UnbondingOperations

They share the same value, which allows for corruption of each other values from completely different parts of the codebase.

BVSS
Recommendation

Change one of them to another value not being used by other keys.

Remediation

SOLVED: Changed the key UnbondingIDKey to 0x40.

Remediation Hash
https://github.com/piplabs/cosmos-sdk/pull/28/commits/123577ba125bbd0099e18c53bee4645f8cdd254b

7.2 Incorrect default period duration

// Low

Description

The default periods have a flaw where the period of type 1 expects Duration of 3 months, but instead, it receives a fixed duration of 30 days.


The definition is wrong:


https://github.com/piplabs/cosmos-sdk/blob/c553dc6734da1d49fcde55efd825d84998051dd7/x/staking/types/params.go#L44C1-L65C2

var DefaultPeriods = []Period{
	{
		PeriodType:        0,
		Duration:          time.Duration(0),
		RewardsMultiplier: math.LegacyOneDec(), // 1
	},
	{
		PeriodType:        1,
		Duration:          time.Hour * 24 * 30,                // 3 months
		RewardsMultiplier: math.LegacyNewDecWithPrec(1051, 3), // 1.051
	},
	{
		PeriodType:        2,
		Duration:          time.Hour * 24 * 365,              // 1 year
		RewardsMultiplier: math.LegacyNewDecWithPrec(116, 2), // 1.16
	},
	{
		PeriodType:        3,
		Duration:          time.Hour * 24 * 30 * 18,          // 18 months
		RewardsMultiplier: math.LegacyNewDecWithPrec(134, 2), // 1.34
	},
}

The second one is wrong, as it receives the wrong duration:


https://github.com/piplabs/cosmos-sdk/blob/c553dc6734da1d49fcde55efd825d84998051dd7/x/staking/types/params.go#L50C1-L54C4

	{
		PeriodType:        1,
		Duration:          time.Hour * 24 * 30,                // 3 months
		RewardsMultiplier: math.LegacyNewDecWithPrec(1051, 3), // 1.051
	},
BVSS
Recommendation

Change the code to:

	{
		PeriodType:        1,
		Duration:          time.Hour * 24 * 30 * 3,                // 3 months
		RewardsMultiplier: math.LegacyNewDecWithPrec(1051, 3), // 1.051
	},
Remediation

SOLVED: Fixed by updating the given durations to its correct values.

Remediation Hash
https://github.com/piplabs/cosmos-sdk/pull/31/commits/f8dcf3924e9ca5ceac8c72debc1bf606b20da697

Halborn strongly recommends conducting a follow-up assessment of the project either within six months or immediately following any material changes to the codebase, whichever comes first. This approach is crucial for maintaining the project’s integrity and addressing potential vulnerabilities introduced by code modifications.

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