CVE-2025-54351
📋 TL;DR
CVE-2025-54351 is a buffer overflow vulnerability in iperf network performance testing tool when using the --skip-rx-copy flag. This allows attackers to execute arbitrary code or cause denial of service on affected systems. Anyone running iperf versions before 3.19.1 with the vulnerable flag is potentially affected.
💻 Affected Systems
- iperf
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Remote code execution leading to complete system compromise, data theft, or lateral movement within the network.
Likely Case
Denial of service causing iperf crashes and potential system instability, with possible information disclosure.
If Mitigated
Limited impact if proper network segmentation and access controls prevent unauthorized access to iperf services.
🎯 Exploit Status
Exploitation requires network access to iperf service and use of specific flag. No public exploits known at this time.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: 3.19.1
Vendor Advisory: https://github.com/esnet/iperf/releases/tag/3.19.1
Restart Required: No
Instructions:
1. Download iperf 3.19.1 from official repository. 2. Compile and install following standard build procedures. 3. Replace existing iperf binary with patched version.
🔧 Temporary Workarounds
Disable vulnerable flag
allPrevent use of --skip-rx-copy flag in iperf commands
# Ensure --skip-rx-copy is not used in any iperf commands
Network access control
linuxRestrict network access to iperf services
# Use firewall rules to limit iperf port access
iptables -A INPUT -p tcp --dport 5201 -s trusted_networks -j ACCEPT
iptables -A INPUT -p tcp --dport 5201 -j DROP
🧯 If You Can't Patch
- Remove iperf from production systems or restrict to isolated test environments
- Implement strict network segmentation and firewall rules to limit iperf service exposure
🔍 How to Verify
Check if Vulnerable:
Check iperf version and verify if --skip-rx-copy flag is used in any scripts or configurationsCheck Version:
iperf --versionVerify Fix Applied:
Run 'iperf --version' and confirm version is 3.19.1 or later📡 Detection & Monitoring
Log Indicators:
- iperf process crashes
- segmentation fault errors in system logs
- unusual network traffic to iperf ports
Network Indicators:
- Traffic to iperf default port 5201 with --skip-rx-copy flag usage
- malformed packets targeting iperf service
SIEM Query:
process_name="iperf" AND (command_line="*--skip-rx-copy*" OR exit_code="139")