CVE-2025-54350 in iperf3
Summary
by MITRE • 08/03/2025
In iperf before 3.19.1, iperf_auth.c has a Base64Decode assertion failure and application exit upon a malformed authentication attempt.
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Analysis
by VulDB Data Team • 08/21/2025
The vulnerability identified as CVE-2025-54350 affects the iperf network performance measurement tool version 3.19.1 and earlier, specifically within the authentication mechanism implemented in the iperf_auth.c source file. This issue represents a critical security flaw that can be exploited to cause a denial of service condition through deliberate malformed authentication attempts. The vulnerability manifests as a Base64Decode assertion failure that results in the application terminating unexpectedly, effectively disrupting network performance testing operations that rely on iperf for benchmarking and diagnostics.
The technical flaw stems from inadequate input validation within the authentication subsystem where the Base64 decoding function fails to properly handle malformed input data during authentication attempts. When an attacker submits a specially crafted authentication payload containing invalid Base64 encoded data, the assertion check in iperf_auth.c triggers a program termination rather than gracefully handling the error condition. This behavior violates the principle of robust error handling and demonstrates a lack of proper input sanitization mechanisms that should be implemented in security-critical components. The vulnerability aligns with CWE-248, which addresses the issue of an exception being thrown for an unhandled condition, and represents a classic example of improper error handling that leads to application instability.
The operational impact of this vulnerability extends beyond simple service disruption to potentially compromise network monitoring and testing environments that depend on iperf for performance validation. Network administrators and security teams conducting bandwidth testing, latency measurements, or throughput analysis could experience unexpected application crashes when encountering malicious or malformed authentication attempts. This vulnerability is particularly concerning in automated testing environments where iperf may be invoked programmatically, as it could lead to cascading failures in network performance monitoring systems. The issue also presents potential for exploitation in environments where iperf is used for security testing or penetration testing activities, where the denial of service could interfere with legitimate security assessments.
Mitigation strategies for CVE-2025-54350 should prioritize the immediate upgrade to iperf version 3.19.1 or later, which includes the necessary patches to address the Base64 decoding assertion failure. Organizations should also implement network-level controls to restrict access to iperf services and monitor for unusual authentication patterns that might indicate exploitation attempts. Security teams should consider deploying intrusion detection systems that can identify malformed authentication attempts targeting iperf services. Additionally, implementing proper input validation and error handling procedures in custom applications that interface with iperf can provide additional defense-in-depth measures. From an ATT&CK framework perspective, this vulnerability maps to T1499.004, which covers network disruption via denial of service, and represents a specific implementation weakness that could be leveraged in broader attack campaigns targeting network infrastructure performance testing tools. Organizations should also conduct thorough security testing to ensure that the patched version properly handles all edge cases in authentication input validation without introducing regressions in functionality.