The arc4random function in the kernel in FreeBSD 6.3 through 7.1 does not have a proper entropy source for a short time period immediately after boot, which makes it easier for attackers to predict the function's return values and conduct certain attacks against the GEOM framework and various network protocols, related to the Yarrow random number generator.
The TCP implementation in (1) Linux, (2) platforms based on BSD Unix, (3) Microsoft Windows, (4) Cisco products, and probably other operating systems allows remote attackers to cause a denial of service (connection queue exhaustion) via multiple vectors that manipulate information in the TCP state table, as demonstrated by sockstress.
The IPv6 Neighbor Discovery Protocol (NDP) implementation in (1) FreeBSD 6.3 through 7.1, (2) OpenBSD 4.2 and 4.3, (3) NetBSD, (4) Force10 FTOS before E7.7.1.1, (5) Juniper JUNOS, and (6) Wind River VxWorks 5.x through 6.4 does not validate the origin of Neighbor Discovery messages, which allows remote attackers to cause a denial of service (loss of connectivity) or read private network traffic via a spoofed message that modifies the Forward Information Base (FIB).
The mld_input function in sys/netinet6/mld6.c in the kernel in NetBSD 4.0, FreeBSD, and KAME, when INET6 is enabled, allows remote attackers to cause a denial of service (divide-by-zero error and panic) via a malformed ICMPv6 Multicast Listener Discovery (MLD) query with a certain Maximum Response Delay value.
sys/netinet6/icmp6.c in the kernel in FreeBSD 6.3 through 7.1, NetBSD 3.0 through 4.0, and possibly other operating systems does not properly check the proposed new MTU in an ICMPv6 Packet Too Big Message, which allows remote attackers to cause a denial of service (panic) via a crafted Packet Too Big Message.
The kernel in FreeBSD 6.3 through 7.0 on amd64 platforms can make an extra swapgs call after a General Protection Fault (GPF), which allows local users to gain privileges by triggering a GPF during the kernel's return from (1) an interrupt, (2) a trap, or (3) a system call.
Stack-based buffer overflow in NConvert 4.92, GFL SDK 2.82, and XnView 1.93.6 on Windows and 1.70 on Linux and FreeBSD allows user-assisted remote attackers to execute arbitrary code via a crafted format keyword in a Sun TAAC file.
Stack-based buffer overflow in the command_Expand_Interpret function in command.c in ppp (aka user-ppp), as distributed in FreeBSD 6.3 and 7.0, OpenBSD 4.1 and 4.2, and the net/userppp package for NetBSD, allows local users to gain privileges via long commands containing "~" characters.
A certain pseudo-random number generator (PRNG) algorithm that uses XOR and 3-bit random hops (aka "Algorithm X3"), as used in OpenBSD 2.8 through 4.2, allows remote attackers to guess sensitive values such as DNS transaction IDs by observing a sequence of previously generated values. NOTE: this issue can be leveraged for attacks such as DNS cache poisoning against OpenBSD's modification of BIND.
A certain pseudo-random number generator (PRNG) algorithm that uses XOR and 2-bit random hops (aka "Algorithm X2"), as used in OpenBSD 2.6 through 3.4, Mac OS X 10 through 10.5.1, FreeBSD 4.4 through 7.0, and DragonFlyBSD 1.0 through 1.10.1, allows remote attackers to guess sensitive values such as IP fragmentation IDs by observing a sequence of previously generated values. NOTE: this issue can be leveraged for attacks such as injection into TCP packets and OS fingerprinting.