CVE-2025-49015
📋 TL;DR
The Couchbase .NET SDK before version 3.7.1 has a TLS certificate validation vulnerability where hostname verification is disabled by default. This allows potential man-in-the-middle attacks by accepting invalid certificates. All applications using affected versions of the Couchbase .NET client library are impacted.
💻 Affected Systems
- Couchbase .NET SDK
📦 What is this software?
.net Sdk by Couchbase
⚠️ Risk & Real-World Impact
Worst Case
Attackers could intercept and manipulate all database communications, potentially stealing sensitive data or injecting malicious queries.
Likely Case
Man-in-the-middle attackers in privileged network positions could eavesdrop on database communications or perform credential theft.
If Mitigated
With proper network segmentation and certificate validation, risk is limited to internal network attacks only.
🎯 Exploit Status
Exploitation requires network access to intercept TLS connections between client and Couchbase server.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: 3.7.1
Vendor Advisory: https://www.couchbase.com/alerts/
Restart Required: Yes
Instructions:
1. Update Couchbase .NET SDK NuGet package to version 3.7.1 or later. 2. Rebuild and redeploy affected applications. 3. Restart application services.
🔧 Temporary Workarounds
Enable TLS hostname verification manually
allConfigure the Couchbase client to enable hostname verification in application code
// C# example: new ClusterOptions().WithTls(true).WithHostnameVerification(true)
🧯 If You Can't Patch
- Implement network segmentation to isolate Couchbase traffic from untrusted networks
- Use certificate pinning or custom certificate validation callbacks in application code
🔍 How to Verify
Check if Vulnerable:
Check the Couchbase .NET SDK package version in your project. If version is less than 3.7.1, you are vulnerable.Check Version:
dotnet list package | findstr CouchbaseVerify Fix Applied:
Verify the installed Couchbase .NET SDK package version is 3.7.1 or higher and test TLS connections validate hostnames properly.📡 Detection & Monitoring
Log Indicators:
- TLS handshake failures with certificate validation errors
- Unexpected IP address connections to Couchbase servers
Network Indicators:
- Unencrypted or improperly validated TLS connections to Couchbase ports
- MITM attack patterns in network traffic
SIEM Query:
source="application_logs" AND ("Couchbase" AND "certificate" AND "validation")