CVE-2024-40636
📋 TL;DR
This vulnerability in Steeltoe's Eureka discovery client logs authentication credentials when multiple Eureka server URLs with basic authentication are configured and registry fetching fails. Only the first URL is properly masked, potentially exposing credentials in log files. Organizations using Steeltoe.Discovery.Eureka with multiple Eureka servers and basic authentication are affected.
💻 Affected Systems
- Steeltoe.Discovery.Eureka
⚠️ Manual Verification Required
This CVE does not have specific version information in our database, so automatic vulnerability detection cannot determine if your system is affected.
Why? The CVE database entry doesn't specify which versions are vulnerable (no version ranges provided by the vendor/NVD).
🔒 Custom verification scripts are available for registered users. Sign up free to download automated test scripts.
- Review the CVE details at NVD
- Check vendor security advisories for your specific version
- Test if the vulnerability is exploitable in your environment
- Consider updating to the latest version as a precaution
⚠️ Risk & Real-World Impact
Worst Case
Attackers gain access to Eureka server credentials, potentially compromising service discovery infrastructure and enabling further attacks on microservices.
Likely Case
Credentials exposed in log files accessible to unauthorized personnel or attackers with log access, leading to potential credential misuse.
If Mitigated
Limited exposure if logs are properly secured with restricted access and monitoring.
🎯 Exploit Status
Exploitation requires access to application logs where the error is recorded.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: 3.2.8
Vendor Advisory: https://github.com/SteeltoeOSS/security-advisories/security/advisories/GHSA-vmcp-66r5-3pcp
Restart Required: Yes
Instructions:
1. Update Steeltoe.Discovery.Eureka NuGet package to version 3.2.8 or later. 2. Rebuild and redeploy affected applications. 3. Restart application services.
🔧 Temporary Workarounds
Disable detailed error logging
allConfigure logging to exclude detailed error messages or mask sensitive information at the logging framework level.
Configure log filtering in appsettings.json or programmatically to exclude DiscoveryClient error logs
Use single Eureka server URL
allConfigure only one Eureka server URL if possible to avoid the multiple URL parsing issue.
Set Eureka:Client:ServiceUrl to single URL in configuration
🧯 If You Can't Patch
- Implement strict access controls on log files and directories containing application logs.
- Monitor log files for credential exposure patterns and implement alerting for suspicious access.
🔍 How to Verify
Check if Vulnerable:
Check if using Steeltoe.Discovery.Eureka version <3.2.8 with multiple Eureka server URLs configured with basic authentication.Check Version:
dotnet list package Steeltoe.Discovery.EurekaVerify Fix Applied:
Verify Steeltoe.Discovery.Eureka package version is 3.2.8 or higher in project dependencies.📡 Detection & Monitoring
Log Indicators:
- Log entries containing 'FetchRegistry Failed for Eureka service urls:' with unmasked URLs containing credentials
Network Indicators:
- Unusual authentication attempts to Eureka servers using potentially exposed credentials
SIEM Query:
source="application_logs" AND "FetchRegistry Failed for Eureka service urls:" AND ("http://" OR "https://") AND ("@" OR "password")