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.
Integer overflow in banner/banner.c in FreeBSD, NetBSD, and OpenBSD might allow local users to modify memory via a long banner. NOTE: CVE and multiple third parties dispute this issue. Since banner is not setuid, an exploit would not cross privilege boundaries in normal operations. This issue is not a vulnerability
The _dl_unsetenv function in loader.c in the ELF ld.so in OpenBSD 3.9 and 4.0 does not properly remove duplicate environment variables, which allows local users to pass dangerous variables such as LD_PRELOAD to loading processes, which might be leveraged to gain privileges.
Unspecified vulnerability in the sshd Privilege Separation Monitor in OpenSSH before 4.5 causes weaker verification that authentication has been successful, which might allow attackers to bypass authentication. NOTE: as of 20061108, it is believed that this issue is only exploitable by leveraging vulnerabilities in the unprivileged process, which are not known to exist.
The kernel in FreeBSD 6.1 and OpenBSD 4.0 allows local users to cause a denial of service via unspecified vectors involving certain ioctl requests to /dev/crypto.
OpenSSH portable 4.1 on SUSE Linux, and possibly other platforms and versions, and possibly under limited configurations, allows remote attackers to determine valid usernames via timing discrepancies in which responses take longer for valid usernames than invalid ones, as demonstrated by sshtime. NOTE: as of 20061014, it appears that this issue is dependent on the use of manually-set passwords that causes delays when processing /etc/shadow due to an increased number of rounds.
Integer overflow in the systrace_preprepl function (STRIOCREPLACE) in systrace in OpenBSD 3.9 and NetBSD 3 allows local users to cause a denial of service (crash), gain privileges, or read arbitrary kernel memory via large numeric arguments to the systrace ioctl.
packet.c in ssh in OpenSSH allows remote attackers to cause a denial of service (crash) by sending an invalid protocol sequence with USERAUTH_SUCCESS before NEWKEYS, which causes newkeys[mode] to be NULL.