Ripple - Smart Contract Audit - Credentials Audit | Ripple

Summary

100% of all REPORTED Findings have been addressed

About this report

Assessment Type

Assurance Assessment

Date of Engagement

January 6th, 2025 - January 30th, 2025

Source Code

rippled

Assessed Commit ID

cd9b5c9

Severity Breakdown

3Acknowledged
4Risk Accepted
1Solved
8All Findings

Critical0
High0
Medium2
- 2Risk A.
Low2
- 2Risk A.
Informational4
- 3Ack.
- 1Solved

Introduction#

Ripple engaged Halborn to conduct a security assessment on XRP Ledger (XRPL) feature amendments beginning on January 6th, 2025 and ending on January 30th, 2025, focusing on modifications to the codebase between the commit 4c2e6a3 and the commit cd9b5c9. The review specifically targets changes introduced during these commits, assuming the validity of the pre-existing logic and excluding verification of its security, e.g., input validation of previously existing parameters.

The Credentials feature introduced new transaction validation mechanisms and structures that allow credential-based authorization within the Ripple network. This feature enables accounts to issue, manage, and verify credentials for transaction approval, adding an additional layer of security and control.

Assessment Summary#

The team at Halborn assigned a full-time security engineer to assess the security of the node. The security engineer is a blockchain and smart-contract security expert in advanced penetration testing, smart-contract hacking, and deep knowledge of multiple blockchain protocols.

The purpose of this assessment is to:

Ensure that the new features operate as intended.
Identify potential security issues with the new features.

In summary, Halborn identified some improvements to reduce the likelihood and impact of risks, which were mostly acknowledged by the Ripple team. The main ones were the following:

Ensure that expired NFT offers and credentials are handled separately by using distinct error codes.
Explicitly reject transactions signed with a disabled Master Key, even if it is also set as the Regular Key.
Replace assertions with explicit error handling that operates in all build configurations.
Include a check that confirms whether the recipient has configured Deposit Auth before invoking verifyDepositPreauth.

Test Approach and Methodology#

Halborn performed a combination of manual review of the code and automated security testing to balance efficiency, timeliness, practicality, and accuracy in regard to the scope of the node security assessment. While manual testing is recommended to uncover flaws in logic, process, and implementation; automated testing techniques help enhance coverage 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 the architecture, purpose, and use of the platform.
Manual code review and walkthrough to identify any logic issue.
Graphing out functionality and contract logic/connectivity/functions.

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:

EXPLOITABILITY METRIC ( $m_e$ )	METRIC VALUE	NUMERICAL VALUE
Attack Origin (AO)	Arbitrary (AO:A)	1
Attack Origin (AO)	Specific (AO:S)	0.2
Attack Cost (AC)	Low (AC:L)	1
	Medium (AC:M)	0.67
	High (AC:H)	0.33
Attack Complexity (AX)	Low (AX:L)	1
	Medium (AX:M)	0.67
	High (AX:H)	0.33

Exploitability

E

is calculated using the following formula:

$E = \prod m_e$

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 ( $m_I$ )	METRIC VALUE	NUMERICAL VALUE
Confidentiality (C)	None (C:N)	0
	Low (C:L)	0.25
	Medium (C:M)	0.5
	High (C:H)	0.75
	Critical (C:C)	1
Integrity (I)	None (I:N)	0
	Low (I:L)	0.25
	Medium (I:M)	0.5
	High (I:H)	0.75
	Critical (I:C)	1
Availability (A)	None (A:N)	0
	Low (A:L)	0.25
	Medium (A:M)	0.5
	High (A:H)	0.75
	Critical (A:C)	1
Deposit (D)	None (D:N)	0
	Low (D:L)	0.25
	Medium (D:M)	0.5
	High (D:H)	0.75
	Critical (D:C)	1
Yield (Y)	None (Y:N)	0
	Low (Y:L)	0.25
	Medium (Y:M)	0.5
	High (Y:H)	0.75
	Critical (Y:C)	1

Impact

I

is calculated using the following formula:

$I = max(m_I) + \frac{\sum{m_I} - max(m_I)}{4}$

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 ( $C$ )	COEFFICIENT VALUE	NUMERICAL VALUE
Reversibility ( $r$ )	None (R:N)	1
	Partial (R:P)	0.5
	Full (R:F)	0.25
Scope ( $s$ )	Changed (S:C)	1.25
Scope ( $s$ )	Unchanged (S:U)	1

Severity Coefficient

C

is obtained by the following product:

$C = rs$

The Vulnerability Severity Score

S

is obtained by:

$S = min(10, EIC * 10)$

The score is rounded up to 1 decimal places.

Critical	High	Medium	Low	Informational
9 - 10	7 - 8.9	4.5 - 6.9	2 - 4.4	0 - 1.9

Scope#

(a) Repository:rippled

(b) Assessed Commit ID:cd9b5c92108b3973ea6e42084db3248bfeb53e8b

19 files

src

19 files

libxrpl / protocol

4 files

ErrorCodes.cpp

cpp

Indexes.cpp

cpp

InnerObjectFormats.cpp

cpp

TER.cpp

cpp

xrpld

15 files

app

11 files

main

1 file

Main.cpp

cpp

misc

1 file

CredentialHelpers.cpp

cpp

Out-of-Scope:The review specifically targets changes introduced during the commit 4c2e6a3 and the commit cd9b5c9, assuming the validity of the pre-existing logic and excluding verification of its security, e.g., input validation of previously existing parameters.

Out-of-Scope: New features/implementations after the remediation commit IDs.

Assessment Summary & Findings Overview#

#	Title	Severity	Score	Status
HAL-01	Incorrect handling of expired Credentials and NFT offers	Medium	5.0	Risk Accepted02/18/2025
HAL-02	Master Key persistence allows transactions despite being disabled	Medium	5.0	Risk Accepted01/28/2025
HAL-03	Assertions may lead to inconsistent behavior in production	Low	3.4	Risk Accepted02/18/2025
HAL-04	Inconsistent credential handling when Deposit Auth is not configured	Low	2.1	Risk Accepted02/18/2025
HAL-05	Incorrect error code for duplicate credential entries	Informational	1.7	Acknowledged03/16/2025
HAL-06	Misleading error handling for invalid ledger index values	Informational	0.8	Solved03/11/2025
HAL-07	Expiration validation in doApply rather than preclaim	Informational	0.6	Acknowledged02/18/2025
HAL-08	Inability to replace an expired credential due to duplicate checks	Informational	0.3	Acknowledged02/26/2025

Remediation Comment

Disclaimer#

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.