CVE-2025-29776
Remediation/Mitigation Strategy for CVE-2025-29776 - Azle setTimer Infinite Loop
Vulnerability Description:
The setTimer function in Azle versions 0.27.0, 0.28.0, and 0.29.0 causes an immediate infinite loop of timers to be executed on the canister. Each timer attempts to clean up the global state of the previous timer, leading to resource exhaustion and denial of service. The infinite loop is triggered by any valid invocation of setTimer.
Severity:
- CVSS Score: 8.7 (High)
- Impact: Denial of Service (DoS), Resource Exhaustion, Potential Canister Unresponsiveness
Known Exploit:
The vulnerability is trivially exploitable. Simply calling setTimer within an Azle canister running one of the affected versions will trigger the infinite loop. No specific attacker skill or crafted input is required.
Remediation Strategy:
The primary and recommended remediation strategy is to upgrade to Azle version 0.30.0 or later. This version contains the fix for the setTimer infinite loop vulnerability.
Mitigation Strategy (If Upgrade is Not Immediately Possible):
If an immediate upgrade to Azle 0.30.0 is not feasible, the following workaround can be implemented to recover a canister caught in the infinite loop:
- Upgrade the Canister: The act of upgrading the canister will clear all existing timers, effectively ending the infinite loop. This requires the ability to deploy a new version of the canister.
Detailed Steps:
Identify Affected Canisters: Determine which canisters are running Azle versions 0.27.0, 0.28.0, or 0.29.0.
Upgrade Canisters (Recommended):
- Preparation: Obtain or build a new version of the canister that uses Azle
0.30.0or later. - Deployment: Deploy the new canister version to the Internet Computer. The specific deployment process will depend on the tooling and platform used to manage the canister.
- Preparation: Obtain or build a new version of the canister that uses Azle
Mitigation (If Immediate Upgrade Not Possible):
- Monitor: If you suspect a canister is in the infinite loop due to excessive resource consumption or unresponsiveness, attempt the upgrade process as outlined in Step 2.
Long-Term Preventative Measures:
- Vulnerability Monitoring: Subscribe to security advisories from GitHub, Azle, and other relevant sources to stay informed about potential vulnerabilities.
- Dependency Management: Implement a robust dependency management strategy to track and manage the versions of all libraries and runtimes used in your canisters.
- Regular Updates: Establish a process for regularly updating dependencies and runtime environments to address known vulnerabilities.
- Testing: Implement thorough testing procedures, including fuzzing and security audits, to identify potential vulnerabilities before deployment.
Example Code (Illustrative of the Vulnerability - DO NOT USE IN PRODUCTION): typescript // Example demonstrating the vulnerability in Azle versions 0.27.0 - 0.29.0
// THIS CODE IS FOR ILLUSTRATION PURPOSES ONLY. DO NOT DEPLOY TO PRODUCTION.
import { setTimer, Principal } from ‘azle’;
export function triggerLoop(): void { console.log(“Triggering timer…”); setTimer(1000, () => { // Sets a timer for 1 second console.log(“Timer executed!”); // In vulnerable versions, this triggers an infinite loop. }); }
Disclaimer: This information is provided for educational and informational purposes only. The specific steps required for remediation and mitigation may vary depending on your environment and tooling. Consult with security professionals for tailored guidance.
Assigner
- GitHub, Inc. [email protected]
Date
- Published Date: 2025-03-14 13:13:27
- Updated Date: 2025-03-14 14:15:19