CVE-2024-26455
📋 TL;DR
CVE-2024-26455 is a use-after-free vulnerability in fluent-bit's custom_calyptia plugin that could allow attackers to execute arbitrary code or cause denial of service. This affects systems running fluent-bit 2.2.2 with the custom_calyptia plugin enabled. Attackers could potentially gain control of the fluent-bit process.
💻 Affected Systems
- fluent-bit
📦 What is this software?
Fluent Bit by Treasuredata
⚠️ Risk & Real-World Impact
Worst Case
Remote code execution leading to complete system compromise, data exfiltration, or lateral movement within the network.
Likely Case
Denial of service causing fluent-bit to crash, disrupting log collection and monitoring capabilities.
If Mitigated
Limited impact if plugin is disabled or system has proper isolation and minimal privileges.
🎯 Exploit Status
Exploitation requires sending specially crafted data to the custom_calyptia plugin endpoint.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: 2.2.3
Vendor Advisory: https://github.com/fluent/fluent-bit/security/advisories
Restart Required: Yes
Instructions:
1. Upgrade fluent-bit to version 2.2.3 or later. 2. Stop fluent-bit service. 3. Install updated version. 4. Restart fluent-bit service.
🔧 Temporary Workarounds
Disable custom_calyptia plugin
allRemove or comment out custom_calyptia plugin configuration to prevent exploitation.
# Edit fluent-bit configuration file
# Remove or comment out [INPUT] or [FILTER] sections using custom_calyptia
🧯 If You Can't Patch
- Disable custom_calyptia plugin in configuration
- Implement network segmentation to restrict access to fluent-bit endpoints
🔍 How to Verify
Check if Vulnerable:
Check fluent-bit version and configuration for custom_calyptia plugin usage.Check Version:
fluent-bit --versionVerify Fix Applied:
Verify fluent-bit version is 2.2.3 or later and check that service runs without errors.📡 Detection & Monitoring
Log Indicators:
- Segmentation fault or crash logs from fluent-bit
- Unexpected memory access errors
Network Indicators:
- Unusual traffic to custom_calyptia plugin endpoints
SIEM Query:
source="fluent-bit" AND ("segmentation fault" OR "use-after-free" OR "crash")