httpd in OpenBSD allows remote attackers to cause a denial of service (memory consumption) via a series of requests for a large file using an HTTP Range header.

regcomp in the BSD implementation of libc is vulnerable to denial of service due to stack exhaustion.

sshd in OpenSSH before 4.4, when using the version 1 SSH protocol, allows remote attackers to cause a denial of service (CPU consumption) via an SSH packet that contains duplicate blocks, which is not properly handled by the CRC compensation attack detector.

The tcp_respond function in netinet/tcp_subr.c in OpenBSD 4.1 and 4.2 allows attackers to cause a denial of service (panic) via crafted TCP packets. NOTE: some of these details are obtained from third party information.

The pf_test_rule function in OpenBSD Packet Filter (PF), as used in OpenBSD 4.2 through 4.5, NetBSD 5.0 before RC3, MirOS 10 and earlier, and MidnightBSD 0.3-current allows remote attackers to cause a denial of service (panic) via crafted IP packets that trigger a NULL pointer dereference during translation, related to an IPv4 packet with an ICMPv6 payload.

The kex_input_kexinit function in kex.c in OpenSSH 6.x and 7.x through 7.3 allows remote attackers to cause a denial of service (memory consumption) by sending many duplicate KEXINIT requests. NOTE: a third party reports that "OpenSSH upstream does not consider this as a security issue."

The auth_password function in auth-passwd.c in sshd in OpenSSH before 7.3 does not limit password lengths for password authentication, which allows remote attackers to cause a denial of service (crypt CPU consumption) via a long string.

The sys_thrsigdivert function in kern/kern_sig.c in the OpenBSD kernel 5.9 allows remote attackers to cause a denial of service (panic) via a negative "ts.tv_sec" value.

The IPv6 protocol allows remote attackers to cause a denial of service via crafted IPv6 type 0 route headers (IPV6_RTHDR_TYPE_0) that create network amplification between two routers.