Integer overflow in the calloc function in libc/stdlib/malloc.c in jemalloc in libc for FreeBSD 6.4 and NetBSD makes it easier for context-dependent attackers to perform memory-related attacks such as buffer overflows via a large size value, which triggers a memory allocation of one byte.

The getnameinfo function in FreeBSD 4.1.1 and earlier, and possibly other operating systems, allows a remote attacker to cause a denial of service via a long DNS hostname.

telnetd in FreeBSD 4.2 and earlier, and possibly other operating systems, allows remote attackers to cause a denial of service by specifying an arbitrary large file in the TERMCAP environmental variable, which consumes resources as the server processes the file.

The libarchive library in FreeBSD 6-STABLE after 2006-09-05 and before 2006-11-08 allows context-dependent attackers to cause a denial of service (CPU consumption) via a malformed archive that causes libarchive to skip a region past the actual end of the archive, which triggers an infinite loop that attempts to read more data.

OpenSSH on FreeBSD 5.3 and 5.4, when used with OpenPAM, does not properly handle when a forked child process terminates during PAM authentication, which allows remote attackers to cause a denial of service (client connection refusal) by connecting multiple times to the SSH server, waiting for the password prompt, then disconnecting.

The ipfw firewall in FreeBSD 6.0-RELEASE allows remote attackers to cause a denial of service (firewall crash) via ICMP IP fragments that match a reset, reject or unreach action, which leads to an access of an uninitialized pointer.

Selective Acknowledgement (SACK) in FreeBSD 5.3 and 5.4 does not properly handle an incoming selective acknowledgement when there is insufficient memory, which might allow remote attackers to cause a denial of service (infinite loop).

A logic error in the IP fragment cache functionality in pf in FreeBSD 5.3, 5.4, and 6.0, and OpenBSD, when a 'scrub fragment crop' or 'scrub fragment drop-ovl' rule is being used, allows remote attackers to cause a denial of service (crash) via crafted packets that cause a packet fragment to be inserted twice.

Multiple TCP implementations with Protection Against Wrapped Sequence Numbers (PAWS) with the timestamps option enabled allow remote attackers to cause a denial of service (connection loss) via a spoofed packet with a large timer value, which causes the host to discard later packets because they appear to be too old.

In FreeBSD 13.0-STABLE before n245765-bec0d2c9c841, 12.2-STABLE before r369859, 11.4-STABLE before r369866, 13.0-RELEASE before p1, 12.2-RELEASE before p7, and 11.4-RELEASE before p10, missing message validation in libradius(3) could allow malicious clients or servers to trigger denial of service in vulnerable servers or clients respectively.

OpenBSD 3.4 and NetBSD 1.6 and 1.6.1 allow remote attackers to cause a denial of service (crash) by sending an IPv6 packet with a small MTU to a listening port and then issuing a TCP connect to that port.

TCP, when using a large Window Size, makes it easier for remote attackers to guess sequence numbers and cause a denial of service (connection loss) to persistent TCP connections by repeatedly injecting a TCP RST packet, especially in protocols that use long-lived connections, such as BGP.

FreeBSD 5.1 and earlier, and Mac OS X before 10.3.4, allows remote attackers to cause a denial of service (resource exhaustion of memory buffers and system crash) via a large number of out-of-sequence TCP packets, which prevents the operating system from creating new connections.

OpenSSL 0.9.6 before 0.9.6d does not properly handle unknown message types, which allows remote attackers to cause a denial of service (infinite loop), as demonstrated using the Codenomicon TLS Test Tool.

The SSL/TLS handshaking code in OpenSSL 0.9.7a, 0.9.7b, and 0.9.7c, when using Kerberos ciphersuites, does not properly check the length of Kerberos tickets during a handshake, which allows remote attackers to cause a denial of service (crash) via a crafted SSL/TLS handshake that causes an out-of-bounds read.

The do_change_cipher_spec function in OpenSSL 0.9.6c to 0.9.6k, and 0.9.7a to 0.9.7c, allows remote attackers to cause a denial of service (crash) via a crafted SSL/TLS handshake that triggers a null dereference.

The arplookup function in FreeBSD 5.1 and earlier, Mac OS X before 10.2.8, and possibly other BSD-based systems, allows remote attackers on a local subnet to cause a denial of service (resource starvation and panic) via a flood of spoofed ARP requests.

The DNS map code in Sendmail 8.12.8 and earlier, when using the "enhdnsbl" feature, does not properly initialize certain data structures, which allows remote attackers to cause a denial of service (process crash) via an invalid DNS response that causes Sendmail to free incorrect data.

BIND 8.x through 8.3.3 allows remote attackers to cause a denial of service (crash) via SIG RR elements with invalid expiry times, which are removed from the internal BIND database and later cause a null dereference.

BIND 8.3.x through 8.3.3 allows remote attackers to cause a denial of service (termination due to assertion failure) via a request for a subdomain that does not exist, with an OPT resource record with a large UDP payload size.

IPSEC implementations including (1) FreeS/WAN and (2) KAME do not properly calculate the length of authentication data, which allows remote attackers to cause a denial of service (kernel panic) via spoofed, short Encapsulating Security Payload (ESP) packets, which result in integer signedness errors.

The accept_filter mechanism in FreeBSD 4 through 4.5 does not properly remove entries from the incomplete listen queue when adding a syncache, which allows remote attackers to cause a denial of service (network service availability) via a large number of connection attempts, which fills the queue.

Network File System (NFS) in FreeBSD 4.6.1 RELEASE-p7 and earlier, NetBSD 1.5.3 and earlier, and possibly other operating systems, allows remote attackers to cause a denial of service (hang) via an RPC message with a zero length payload, which causes NFS to reference a previous payload and enter an infinite loop.

Memory leak in FreeBSD 4.5 and earlier allows remote attackers to cause a denial of service (memory exhaustion) via ICMP echo packets that trigger a bug in ip_output() in which the reference count for a routing table entry is not decremented, which prevents the entry from being removed.

SGI IRIX 6.5 through 6.5.12f and possibly earlier versions, and FreeBSD 3.0, allows remote attackers to cause a denial of service via a malformed IGMP multicast packet with a small response delay.

Multiple TCP implementations could allow remote attackers to cause a denial of service (bandwidth and CPU exhaustion) by setting the maximum segment size (MSS) to a very small number and requesting large amounts of data, which generates more packets with less TCP-level data that amplify network traffic and consume more server CPU to process.

NetBSD 1.5 and earlier and FreeBSD 4.3 and earlier allows a remote attacker to cause a denial of service by sending a large number of IP fragments to the machine, exhausting the mbuf pool.

traceroute in NetBSD 1.3.3 and Linux systems allows local users to flood other systems by providing traceroute with a large waittime (-w) option, which is not parsed properly and sets the time delay for sending packets to zero.

NetBSD 1.4.2 and earlier allows remote attackers to cause a denial of service by sending a packet with an unaligned IP timestamp option.

Vulnerability when Network Address Translation (NAT) is enabled in Linux 2.2.10 and earlier with ipchains, or FreeBSD 3.2 with ipfw, allows remote attackers to cause a denial of service (kernel panic) via a ping -R (record route) command.

Jolt ICMP attack causes a denial of service in Windows 95 and Windows NT systems.

ICMP messages to broadcast addresses are allowed, allowing for a Smurf attack that can cause a denial of service.

FreeBSD allows local users to conduct a denial of service by creating a hard link from a device special file to a file on an NFS file system.

ip_input.c in BSD-derived TCP/IP implementations allows remote attackers to cause a denial of service (crash or hang) via crafted packets.

IP fragmentation denial of service in FreeBSD allows a remote attacker to cause a crash.

TCP RST denial of service in FreeBSD.

Teardrop IP denial of service.

In FreeBSD 12.2-STABLE before r367402, 11.4-STABLE before r368202, 12.2-RELEASE before p1, 12.1-RELEASE before p11 and 11.4-RELEASE before p5 the handler for a routing option caches a pointer into the packet buffer holding the ICMPv6 message. However, when processing subsequent options the packet buffer may be freed, rendering the cached pointer invalid. The network stack may later dereference the pointer, potentially triggering a use-after-free.

The SYN cache (syncache) and SYN cookie (syncookie) mechanism in FreeBSD 4.5 and earlier allows remote attackers to cause a denial of service (crash) (1) via a SYN packet that is accepted using syncookies that causes a null pointer to be referenced for the socket's TCP options, or (2) by killing and restarting a process that listens on the same socket, which does not properly clear the old inpcb pointer on restart.

In FreeBSD 12.0-STABLE before r350637, 12.0-RELEASE before 12.0-RELEASE-p9, 11.3-STABLE before r350638, 11.3-RELEASE before 11.3-RELEASE-p2, and 11.2-RELEASE before 11.2-RELEASE-p13, the bsnmp library is not properly validating the submitted length from a type-length-value encoding. A remote user could cause an out-of-bounds read or trigger a crash of the software such as bsnmpd resulting in a denial of service.

rwho daemon rwhod in FreeBSD 4.2 and earlier, and possibly other operating systems, allows remote attackers to cause a denial of service via malformed packets with a short length.

In FreeBSD 11.x before 11.1-RELEASE and 10.x before 10.4-RELEASE, the qsort algorithm has a deterministic recursion pattern. Feeding a pathological input to the algorithm can lead to excessive stack usage and potential overflow. Applications that use qsort to handle large data set may crash if the input follows the pathological pattern.

BitchX IRC client does not properly cleanse an untrusted format string, which allows remote attackers to cause a denial of service via an invite to a channel whose name includes special formatting characters.

Land IP denial of service.

Denial of Service vulnerability in BIND 8 Releases via maliciously formatted DNS messages.

The MATCH_ASSOC function in NTP before version 4.2.8p9 and 4.3.x before 4.3.92 allows remote attackers to cause an out-of-bounds reference via an addpeer request with a large hmode value.

The inet module in FreeBSD 10.2x before 10.2-PRERELEASE, 10.2-BETA2-p2, 10.2-RC1-p1, 10.1x before 10.1-RELEASE-p16, 9.x before 9.3-STABLE, 9.3-RELEASE-p21, and 8.x before 8.4-STABLE, 8.4-RELEASE-p35 on systems with VNET enabled and at least 16 VNET instances allows remote attackers to cause a denial of service (mbuf consumption) via multiple concurrent TCP connections.