CVE-2021-29508
📋 TL;DR
CVE-2021-29508 is a deserialization vulnerability in Wire serialization library that allows attackers to execute arbitrary code by sending malicious payloads. This affects any application using vulnerable versions of Wire for serialization/deserialization. The vulnerability is similar to the .NET BinaryFormatter issue and allows type confusion attacks.
💻 Affected Systems
- Wire serialization library
- Applications using Wire for serialization
📦 What is this software?
Wire by Asynkron
⚠️ 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
Remote code execution leading to complete system compromise, data theft, and lateral movement within the network.
Likely Case
Remote code execution with the privileges of the application using Wire, potentially allowing data access, service disruption, or further exploitation.
If Mitigated
Limited impact if proper input validation, sandboxing, or network segmentation is in place, though deserialization attacks remain dangerous.
🎯 Exploit Status
The vulnerability is well-documented with public advisories and similar to known .NET BinaryFormatter exploits, making weaponization likely.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Wire 1.0.0 and later
Vendor Advisory: https://github.com/AsynkronIT/Wire/security/advisories/GHSA-hpw7-3vq3-mmv6
Restart Required: Yes
Instructions:
1. Update Wire package to version 1.0.0 or later via NuGet. 2. Update all dependencies that use Wire. 3. Restart affected applications. 4. Test serialization/deserialization functionality.
🔧 Temporary Workarounds
Input validation and type checking
allImplement strict input validation and type checking before deserialization
Use safe serialization alternatives
allReplace Wire with safer serialization formats like JSON or XML with proper schema validation
🧯 If You Can't Patch
- Network segmentation to isolate vulnerable systems from untrusted networks
- Implement application allowlisting and restrict deserialization to trusted sources only
🔍 How to Verify
Check if Vulnerable:
Check if Wire package version is below 1.0.0 in your project dependencies or NuGet packagesCheck Version:
Check package.config or .csproj files for Wire package version, or use NuGet package managerVerify Fix Applied:
Verify Wire package version is 1.0.0 or higher and test deserialization with known safe payloads📡 Detection & Monitoring
Log Indicators:
- Unusual deserialization errors
- Unexpected type conversion exceptions
- Application crashes during deserialization
Network Indicators:
- Unusual serialized data patterns
- Large or malformed serialization payloads
SIEM Query:
Search for application logs containing deserialization errors or exceptions related to Wire serialization