CVE-2025-54349 in iperf3
Summary
by MITRE • 08/03/2025
In iperf before 3.19.1, iperf_auth.c has an off-by-one error and resultant heap-based buffer overflow.
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Analysis
by VulDB Data Team • 02/09/2026
The vulnerability identified as CVE-2025-54349 affects the iperf network performance testing tool version 3.19.1 and earlier, specifically within the iperf_auth.c source file. This issue represents a critical security flaw that arises from improper memory management during authentication processing, creating opportunities for attackers to manipulate program execution flow through memory corruption. The vulnerability manifests as an off-by-one error that leads to a heap-based buffer overflow, fundamentally compromising the integrity of the application's memory operations.
The technical flaw occurs when iperf processes authentication credentials, where the software fails to properly validate the length of incoming data against allocated buffer boundaries. This off-by-one error typically results from arithmetic miscalculations in boundary checks, where the comparison logic incorrectly allows one additional byte to be written beyond the intended buffer limits. When authentication data is processed, the program writes beyond the allocated heap memory region, potentially overwriting adjacent memory structures including function pointers, return addresses, or other critical program state information.
The operational impact of this vulnerability extends beyond simple denial of service scenarios, as it creates potential for arbitrary code execution within the context of the iperf process. Attackers who can control the authentication input stream may exploit this memory corruption to redirect program execution flow, inject malicious code, or manipulate program behavior. The heap-based nature of the overflow means that the vulnerability is particularly challenging to exploit reliably, though it remains a significant threat in environments where iperf is used for network performance testing and monitoring. This vulnerability affects systems where iperf is deployed with authentication enabled, particularly in enterprise network testing scenarios.
Mitigation strategies for CVE-2025-54349 primarily focus on immediate version upgrades to iperf 3.19.1 or later, which contain the necessary patches to address the buffer overflow conditions. System administrators should also implement network segmentation to limit access to iperf services and restrict authentication input validation to prevent exploitation attempts. The vulnerability aligns with CWE-121 heap-based buffer overflow classification and represents a potential pathway for exploitation under the ATT&CK framework's privilege escalation and code execution tactics. Organizations should conduct thorough vulnerability assessments to identify all instances of vulnerable iperf versions within their network infrastructure and ensure proper patch management procedures are in place to prevent similar issues in other network monitoring tools.