OpenBSD 4.2 allows local users to cause a denial of service (kernel panic) by calling the SIOCGIFRTLABEL IOCTL on an interface that does not have a route label, which triggers a NULL pointer dereference when the return value from the rtlabel_id2name function is not checked.
Stack-based buffer overflow in the cons_options function in options.c in dhcpd in OpenBSD 4.0 through 4.2, and some other dhcpd implementations based on ISC dhcp-2, allows remote attackers to execute arbitrary code or cause a denial of service (daemon crash) via a DHCP request specifying a maximum message size smaller than the minimum IP MTU.
Multiple race conditions in the (1) Sudo monitor mode and (2) Sysjail policies in Systrace on NetBSD and OpenBSD allow local users to defeat system call interposition, and consequently bypass access control policy and auditing.
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.
Integer overflow in the bdfReadCharacters function in bdfread.c in (1) X.Org libXfont before 20070403 and (2) freetype 2.3.2 and earlier allows remote authenticated users to execute arbitrary code via crafted BDF fonts, which result in a heap overflow.
Integer overflow in the FontFileInitTable function in X.Org libXfont before 20070403 allows remote authenticated users to execute arbitrary code via a long first line in the fonts.dir file, which results in a heap overflow.
Buffer overflow in kern/uipc_mbuf2.c in OpenBSD 3.9 and 4.0 allows remote attackers to execute arbitrary code via fragmented IPv6 packets due to "incorrect mbuf handling for ICMP6 packets." NOTE: this was originally reported as a denial of service.
OpenBSD before 20070116 allows remote attackers to cause a denial of service (infinite loop and CPU consumption) via certain IPv6 ICMP (aka ICMP6) echo request packets.
Unspecified vulnerability in sys/dev/pci/vga_pci.c in the VGA graphics driver for wscons in OpenBSD 3.9 and 4.0, when the kernel is compiled with the PCIAGP option and a non-AGP device is being used, allows local users to gain privileges via unspecified vectors, possibly related to agp_ioctl NULL pointer reference.
OpenBSD and NetBSD permit usermode code to kill the display server and write to the X.Org /dev/xf86 device, which allows local users with root privileges to reduce securelevel by replacing the System Management Mode (SMM) handler via a write to an SMRAM address within /dev/xf86 (aka the video card memory-mapped I/O range), and then launching the new handler via a System Management Interrupt (SMI), as demonstrated by a write to Programmed I/O port 0xB2.