Iperf3: possible denial of service

A flaw was found in iperf, a utility for testing network performance using TCP, UDP, and SCTP. A malicious or malfunctioning client can send less than the expected amount of data to the iperf server, which can cause the server to hang indefinitely waiting for the remainder or until the connection gets closed. This will prevent other connections to the server, leading to a denial of service.

Pre-Authentication Heap Buffer Overflow in iperf3 RSA Decryption

iperf3 3.20–3.21 (esnet/iperf) has a pre-auth heap buffer overflow in decrypt_rsa_message(): a 256-byte RSA buffer is BIO_read with the attacker-controlled ciphertext length (guard warns only), so an unauthenticated client overflows the heap via an oversized authtoken; fixed in 3.22

Remote unauthenticated heap use‑after‑free in iperf3 3.21

iperf3 3.21 (esnet/iperf) contains a remote, unauthenticated heap use-after-free: the server's per-test watchdog server_timer_proc() frees streams without cancelling/joining their worker threads, so a blocked worker dereferences a freed iperf_stream; fixed in 3.22.

iperf3 < 3.22 UDP Receive Worker Infinite Loop DoS

iperf3 versions prior to 3.22 contains a denial of service vulnerability that allows unauthenticated remote attackers to crash-loop the server's UDP receive worker into an unrecoverable infinite loop by sending a single crafted control-channel parameter message followed by one 16-byte UDP datagram. Attackers can permanently pin the affected per-stream receive thread at approximately 100% CPU usage, rendering the server unusable until forcibly killed with SIGKILL, as the process does not respond to normal control-channel closure.

iperf: Denial of Service in iperf Due to Improper JSON Handling

iperf v3.17.1 was discovered to contain a segmentation violation via the iperf_exchange_parameters() function.

iperf3: vulnerable to marvin attack if the authentication option is used

iPerf3 before 3.17, when used with OpenSSL before 3.2.0 as a server with RSA authentication, allows a timing side channel in RSA decryption operations. This side channel could be sufficient for an attacker to recover credential plaintext. It requires the attacker to send a large number of messages for decryption, as described in "Everlasting ROBOT: the Marvin Attack" by Hubert Kario.

iperf3: iperf Authentication Decode Failure

In iperf before 3.19.1, iperf_auth.c has a Base64Decode assertion failure and application exit upon a malformed authentication attempt.

iperf3: iperf Heap Buffer Overflow

In iperf before 3.19.1, iperf_auth.c has an off-by-one error and resultant heap-based buffer overflow.

iperf3: iperf Buffer Overflow

In iperf before 3.19.1, net.c has a buffer overflow when --skip-rx-copy is used (for MSG_TRUNC in recv).

The parse_string function in cjson.c in the cJSON library mishandles UTF8/16 strings, which allows remote attackers to cause a denial of service (crash) or execute arbitrary code via a non-hex character in a JSON string, which triggers a heap-based buffer overflow.

iperf3: memory allocation hazard and crash

iperf3 before 3.14 allows peers to cause an integer overflow and heap corruption via a crafted length field.