Oracle Contracts Audit | Chiliz | Halborn Audit Reports

Summary

100% of all REPORTED Findings have been addressed

About this report

Assessment Type

Assurance Assessment

Date of Engagement

January 28th, 2026 - January 29th, 2026

Source Code

oracle-contracts

Assessed Commit ID

2d5c174

Severity Breakdown

0Acknowledged
0Risk Accepted
14Solved
14All Findings

Critical0
High0
Medium1
- 1Solved
Low7
- 7Solved
Informational6
- 6Solved

INTRODUCTION#

Chiliz engaged Halborn to conduct a security assessment on their smart contracts beginning on January 28th, 2026 and ending on January 29th, 2026. The security assessment was scoped to the smart contracts provided in the chiliz-chain/oracle-contracts Github repository, provided to the Halborn team. Commit hash and further details can be found in the Scope section of this report.

The reviewed contracts implement a centralized, push-based oracle system where authorized updaters manually publish asset prices on-chain for consumption by other contracts. A factory contract manages the deployment, upgrades, and role-based access control of individual price feed oracles, each exposing a Chainlink-compatible interface.

ASSESSMENT SUMMARY#

Halborn was provided with 2 days for this engagement and assigned a full-time security engineer to assess the security of the smart contracts in scope. The assigned engineer possess deep expertise in blockchain and smart contract security, including hands-on experience with multiple blockchain protocols.

The objective of this assessment is to:

Identify potential security issues within the Chiliz oracles system smart contracts.
Ensure that smart contracts of Chiliz Oracles system functions operate as intended.

In summary, Halborn identified several areas for improvement to reduce the likelihood and impact of security risks, which were fully addressed by the Chiliz team. The main recommendations were:

Implement a mechanism in the factory to upgrade the price feeds.
Allow timestamp age limit to be configurable per price feed.
Update the price/rounds getter functions of the price feeds to be non-reverting.
Apply consistent price validation rules across all update paths.

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 smart contract assessment. While manual testing is recommended to uncover flaws in logic, process, and implementation; automated testing techniques help enhance coverage of smart contracts 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 and purpose of the Chiliz Oracles system contracts.
Manual code review and walkthrough of the Chiliz Oracles in-scope contracts.
Manual assessment of critical Solidity variables and functions to identify potential vulnerability classes.
Manual testing using custom scripts.
Static Analysis of security for scoped contract, and imported functions. (Slither).
Local deployment and testing with (Foundry, Remix IDE).

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:oracle-contracts

(b) Assessed Commit ID:2d5c17497e6b9f3ffff9577de9b3a4b0f65f20e3

Show out-of-scope files (2)

7 files

src

5 files

interfaces

3 files

IAggregatorV3Interface.sol

solidity

IOracleFactory.sol

solidity

IPriceFeed.sol

solidity

OracleFactory.sol

solidity

PriceFeed.sol

solidity

Out-of-Scope:third party dependencies and economic attacks.

3016d3e3373e904659a84e033b0daa771a280c36 b86f760352054590279c1aa6d1669d1925266020 e836d7a89aedd335587e775d98363bc9646b3acb

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

Assessment Summary & Findings Overview#

#	Title	Severity	Score	Status
HAL-01	Incomplete upgrade mechanism	Medium	5.0	Solved02/02/2026
HAL-02	Incompatible reentrancy guard choice in upgradeable design	Low	2.5	Solved02/03/2026
HAL-03	Fixed timestamp age does not reflect asset volatility	Low	2.5	Solved02/03/2026
HAL-04	Inconsistent price validation across update functions	Low	2.5	Solved02/03/2026
HAL-05	Compatibility mismatch between claimed Chainlink behavior and revert read behavior	Low	2.5	Solved02/09/2026
HAL-06	No storage gap defined for future upgrades	Low	2.5	Solved02/09/2026
HAL-07	Round start timestamp is derived from previous round rather than explicit round start	Low	2.5	Solved02/09/2026
HAL-08	Missing factory setters for oracle configuration	Low	2.5	Solved02/19/2026
HAL-09	Factory updater role on price feeds can be revoked	Informational	0.5	Solved02/04/2026
HAL-10	Unnecessary reentrancy protection in non-fund-handling functions	Informational	0.0	Solved02/04/2026
HAL-11	Redundant pause and unpause event emissions	Informational	0.0	Solved02/04/2026
HAL-12	Oracles can be removed without being paused first	Informational	0.0	Solved02/04/2026
HAL-13	Pair name case sensitivity can lead to duplicate oracles	Informational	0.0	Solved02/09/2026
HAL-14	PriceFeed allows multiple updaters without clarity	Informational	0.0	Solved02/09/2026

b86f760352054590279c1aa6d1669d1925266020

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.