FreeBSD 4.1.1 and earlier, and possibly other BSD-based OSes, uses an insufficient random number generator to generate initial TCP sequence numbers (ISN), which allows remote attackers to spoof TCP connections.

licq before 1.0.3 allows remote attackers to execute arbitrary commands via shell metacharacters in a URL.

ipfw and ip6fw in FreeBSD 4.2 and earlier allows remote attackers to bypass access restrictions by setting the ECE flag in a TCP packet, which makes the packet appear to be part of an established connection.

Buffer overflow in mopd (Maintenance Operations Protocol loader daemon) allows remote attackers to execute arbitrary commands via a long file name.

A FreeBSD patch for SSH on 2000-01-14 configures ssh to listen on port 722 as well as port 22, which might allow remote attackers to access SSH through port 722 even if port 22 is otherwise filtered.

Buffer overflow in FreeBSD libmytinfo library allows local users to execute commands via a long TERMCAP environmental variable.

Sysinstall in FreeBSD 2.2.1 and earlier, when configuring anonymous FTP, creates the ftp user without a password and with /bin/date as the shell, which could allow attackers to gain access to certain system resources.

XFree86 xfs command is vulnerable to a symlink attack, allowing local users to create files in restricted directories, possibly allowing them to gain privileges or cause a denial of service.

Arbitrary command execution via metamail package using message headers, when user processes attacker's message using metamail.

Buffer overflow in rwhod on AIX and other operating systems allows remote attackers to execute arbitrary code via a UDP packet with a long hostname.

In FreeBSD 12.1-STABLE before r365010, 11.4-STABLE before r365011, 12.1-RELEASE before p9, 11.4-RELEASE before p3, and 11.3-RELEASE before p13, dhclient(8) fails to handle certain malformed input related to handling of DHCP option 119 resulting a heap overflow. The heap overflow could in principle be exploited to achieve remote code execution. The affected process runs with reduced privileges in a Capsicum sandbox, limiting the immediate impact of an exploit.

In FreeBSD 12.1-STABLE before r360971, 12.1-RELEASE before p5, 11.4-STABLE before r360971, 11.4-BETA1 before p1 and 11.3-RELEASE before p9, libalias does not properly validate packet length resulting in modules causing an out of bounds read/write condition if no checking was built into the module.

iked in OpenIKED, as used in OpenBSD through 6.7, allows authentication bypass because ca.c has the wrong logic for checking whether a public key matches.

In FreeBSD 12.0-STABLE before r349622, 12.0-RELEASE before 12.0-RELEASE-p7, 11.3-PRERELEASE before r349624, 11.3-RC3 before 11.3-RC3-p1, and 11.2-RELEASE before 11.2-RELEASE-p11, a bug in iconv implementation may allow an attacker to write past the end of an output buffer. Depending on the implementation, an attacker may be able to create a denial of service, provoke incorrect program behavior, or induce a remote code execution.

AnyDesk before 5.5.3 on Linux and FreeBSD has a format string vulnerability that can be exploited for remote code execution.

login_radius on OpenBSD 3.2, 3.5, and possibly other versions does not verify the shared secret in a response packet from a RADIUS server, which allows remote attackers to bypass authentication by spoofing server replies.

sshd in OpenSSH 3.2.2, when using YP with netgroups and under certain conditions, may allow users to successfully authenticate and log in with another user's password.

Multiple use-after-free vulnerabilities in libarchive 2.8.4 and 2.8.5 allow remote attackers to cause a denial of service (application crash) or possibly have unspecified other impact via a crafted (1) TAR archive or (2) ISO9660 image.

The NetBSD qsort() function is recursive, and not randomized, an attacker can construct a pathological input array of N elements that causes qsort() to deterministically recurse N/4 times. This allows attackers to consume arbitrary amounts of stack memory and manipulate stack memory to assist in arbitrary code execution attacks. This affects NetBSD 7.1 and possibly earlier versions.

A design flaw in the Z-Modem protocol allows the remote sender of a file to execute arbitrary programs on the client, as implemented in rz in the rzsz module of FreeBSD before 2.1.5, and possibly other programs.

Vacation program allows command execution by remote users through a sendmail command.

Improper bounds checking of the obuf variable in the link_ntoa() function in linkaddr.c of the BSD libc library may allow an attacker to read or write from memory. The full impact and severity depends on the method of exploit and how the library is used by applications. According to analysis by FreeBSD developers, it is very unlikely that applications exist that utilize link_ntoa() in an exploitable manner, and the CERT/CC is not aware of any proof of concept. A blog post describes the functionality of link_ntoa() and points out that none of the base utilities use this function in an exploitable manner. For more information, please see FreeBSD Security Advisory SA-16:37.

FTP servers can allow an attacker to connect to arbitrary ports on machines other than the FTP client, aka FTP bounce.

OpenSSH SSH client before 2.3.0 does not properly disable X11 or agent forwarding, which could allow a malicious SSH server to gain access to the X11 display and sniff X11 events, or gain access to the ssh-agent.

ppp utility in FreeBSD 4.1.1 and earlier does not properly restrict access as specified by the "nat deny_incoming" command, which allows remote attackers to connect to the target system.

In FreeBSD 12.1-STABLE before r356035, 12.1-RELEASE before 12.1-RELEASE-p4, 11.3-STABLE before r356036, and 11.3-RELEASE before 11.3-RELEASE-p8, incomplete packet data validation may result in accessing out-of-bounds memory leading to a kernel panic or other unpredictable results.

In FreeBSD 12.0-RELEASE before 12.0-RELEASE-p13, a missing check in the ipsec packet processor allows reinjection of an old packet to be accepted by the ipsec endpoint. Depending on the higher-level protocol in use over ipsec, this could allow an action to be repeated.

OpenSSH 5.6 and earlier, when J-PAKE is enabled, does not properly validate the public parameters in the J-PAKE protocol, which allows remote attackers to bypass the need for knowledge of the shared secret, and successfully authenticate, by sending crafted values in each round of the protocol, a related issue to CVE-2010-4252.

Buffer overflow in libarchive 3.0 pre-release code allows remote attackers to cause a denial of service (application crash) or possibly have unspecified other impact via a crafted CAB file, which is not properly handled during the reading of Huffman code data within LZX compressed data.

libc in OpenBSD 6.6 allows authentication bypass via the -schallenge username, as demonstrated by smtpd, ldapd, or radiusd. This is related to gen/auth_subr.c and gen/authenticate.c in libc (and login/login.c and xenocara/app/xenodm/greeter/verify.c).

In FreeBSD 12.1-STABLE before r356911, and 12.1-RELEASE before p5, insufficient checking in the cryptodev module allocated the size of a kernel buffer based on a user-supplied length allowing an unprivileged process to trigger a kernel panic.

In FreeBSD 12.1-STABLE before r356035, 12.1-RELEASE before 12.1-RELEASE-p4, 11.3-STABLE before r356036, and 11.3-RELEASE before 11.3-RELEASE-p8, incomplete packet data validation may result in memory access after it has been freed leading to a kernel panic or other unpredictable results.

BZ2_decompress in decompress.c in bzip2 through 1.0.6 has an out-of-bounds write when there are many selectors.

Buffer overflow in the decodearr function in ntpq in ntp 4.2.8p6 through 4.2.8p10 allows remote attackers to execute arbitrary code by leveraging an ntpq query and sending a response with a crafted array.

In FreeBSD 12.1-STABLE before r362281, 11.4-STABLE before r362281, and 11.4-RELEASE before p1, long values in the user-controlled PATH environment variable cause posix_spawnp to write beyond the end of the heap allocated stack possibly leading to arbitrary code execution.

In FreeBSD 12.1-STABLE before r357213, 12.1-RELEASE before 12.1-RELEASE-p2, 12.0-RELEASE before 12.0-RELEASE-p13, 11.3-STABLE before r357214, and 11.3-RELEASE before 11.3-RELEASE-p6, URL handling in libfetch with URLs containing username and/or password components is vulnerable to a heap buffer overflow allowing program misbehavior or malicious code execution.