In OpenBGPD before 8.1, incorrect handling of BGP update data (length of path attributes) set by a potentially distant remote actor may cause the system to incorrectly reset a session. This is fixed in OpenBSD 7.3 errata 006.

x509/x509_verify.c in LibreSSL before 3.4.2, and OpenBSD before 7.0 errata 006, allows authentication bypass because an error for an unverified certificate chain is sometimes discarded.

An issue was discovered in x509/x509_verify.c in LibreSSL before 3.6.1, and in OpenBSD before 7.2 errata 001. x509_verify_ctx_add_chain does not store errors that occur during leaf certificate verification, and therefore an incorrect error is returned. This behavior occurs when there is an installed verification callback that instructs the verifier to continue upon detecting an invalid certificate.

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.

OpenBSD through 6.6 allows local users to escalate to root because a check for LD_LIBRARY_PATH in setuid programs can be defeated by setting a very small RLIMIT_DATA resource limit. When executing chpass or passwd (which are setuid root), _dl_setup_env in ld.so tries to strip LD_LIBRARY_PATH from the environment, but fails when it cannot allocate memory. Thus, the attacker is able to execute their own library code as root.

OpenBSD kernel version <= 6.5 can be forced to create long chains of TCP SACK holes that causes very expensive calls to tcp_sack_option() for every incoming SACK packet which can lead to a denial of service.

The OpenBSD 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 OpenBSD 6.1 and possibly earlier versions.

A flaw exists in OpenBSD's implementation of the stack guard page that allows attackers to bypass it resulting in arbitrary code execution using setuid binaries such as /usr/bin/at. This affects OpenBSD 6.1 and possibly earlier versions.

Multiple integer overflows in the glob implementation in libc in OpenBSD before 4.9 might allow context-dependent attackers to have an unspecified impact via a crafted string, related to the GLOB_APPEND and GLOB_DOOFFS flags, a different issue than CVE-2011-0418.

Integer signedness error in the drm_modeset_ctl function in (1) drivers/gpu/drm/drm_irq.c in the Direct Rendering Manager (DRM) subsystem in the Linux kernel before 2.6.38 and (2) sys/dev/pci/drm/drm_irq.c in the kernel in OpenBSD before 4.9 allows local users to trigger out-of-bounds write operations, and consequently cause a denial of service (system crash) or possibly have unspecified other impact, via a crafted num_crtcs (aka vb_num) structure member in an ioctl argument.

Integer overflow in the fts_build function in fts.c in libc in (1) OpenBSD 4.4 and earlier and (2) Microsoft Interix 6.0 build 10.0.6030.0 allows context-dependent attackers to cause a denial of service (application crash) via a deep directory tree, related to the fts_level structure member, as demonstrated by (a) du, (b) rm, (c) chmod, and (d) chgrp on OpenBSD; and (e) SearchIndexer.exe on Vista Enterprise.

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.

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.

A certain pseudo-random number generator (PRNG) algorithm that uses ADD with 0 random hops (aka "Algorithm A0"), as used in OpenBSD 3.5 through 4.2 and NetBSD 1.6.2 through 4.0, allows remote attackers to guess sensitive values such as (1) DNS transaction IDs or (2) IP fragmentation IDs by observing a sequence of previously generated values. NOTE: this issue can be leveraged for attacks such as DNS cache poisoning, injection into TCP packets, and OS fingerprinting.

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.