OpenBSD

The resend_bytes function in roaming_common.c in the client in OpenSSH 5.x, 6.x, and 7.x before 7.1p2 allows remote servers to obtain sensitive information from process memory by requesting transmission of an entire buffer, as demonstrated by reading a private key.

OpenSSH through 10.0, when common types of DRAM are used, might allow row hammer attacks (for authentication bypass) because the integer value of authenticated in mm_answer_authpassword does not resist flips of a single bit. NOTE: this is applicable to a certain threat model of…

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…

Untrusted search path vulnerability in ssh-agent.c in ssh-agent in OpenSSH before 7.4 allows remote attackers to execute arbitrary local PKCS#11 modules by leveraging control over a forwarded agent-socket.

A vulnerability was found in OpenSSH when the VerifyHostKeyDNS option is enabled. A machine-in-the-middle attack can be performed by a malicious machine impersonating a legit server. This issue occurs due to how OpenSSH mishandles error codes in specific conditions when…

An issue was discovered in OpenSSH 7.9. Due to missing character encoding in the progress display, a malicious server (or Man-in-The-Middle attacker) can employ crafted object names to manipulate the client output, e.g., by using ANSI control codes to hide additional files being…

In ssh in OpenSSH before 9.6, OS command injection might occur if a user name or host name has shell metacharacters, and this name is referenced by an expansion token in certain situations. For example, an untrusted Git repository can have a submodule with shell metacharacters…

OpenSSH 7.7 through 7.9 and 8.x before 8.1, when compiled with an experimental key type, has a pre-authentication integer overflow if a client or server is configured to use a crafted XMSS key. This leads to memory corruption and local code execution because of an error in the…

The shared memory manager (associated with pre-authentication compression) in sshd in OpenSSH before 7.4 does not ensure that a bounds check is enforced by all compilers, which might allows local users to gain privileges by leveraging access to a sandboxed privilege-separation…

The do_setup_env function in session.c in sshd in OpenSSH through 7.2p2, when the UseLogin feature is enabled and PAM is configured to read .pam_environment files in user home directories, allows local users to gain privileges by triggering a crafted environment for the…

ssh in OpenSSH before 10.4 can have a use-after-free when a server changes its host key during a key re-exchange. (This outcome occurs only on the client side.)

sshd in OpenSSH before 7.4 allows remote attackers to cause a denial of service (NULL pointer dereference and daemon crash) via an out-of-sequence NEWKEYS message, as demonstrated by Honggfuzz, related to kex.c and packet.c.

The auth_parse_options function in auth-options.c in sshd in OpenSSH before 5.7 provides debug messages containing authorized_keys command options, which allows remote authenticated users to obtain potentially sensitive information by reading these messages, as demonstrated by…

smtpd/lka_filter.c in OpenSMTPD before 6.8.0p1, in certain configurations, allows remote attackers to cause a denial of service (NULL pointer dereference and daemon crash) via a crafted pattern of client activity, because the filter state machine does not properly maintain the…

smtpd/table.c in OpenSMTPD before 6.8.0p1 lacks a certain regfree, which might allow attackers to trigger a "very significant" memory leak via messages to an instance that performs many regex lookups.

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.

sshd in OpenSSH before 7.4, when privilege separation is not used, creates forwarded Unix-domain sockets as root, which might allow local users to gain privileges via unspecified vectors, related to serverloop.c.

The verify_host_key function in sshconnect.c in the client in OpenSSH 6.6 and earlier allows remote servers to trigger the skipping of SSHFP DNS RR checking by presenting an unacceptable HostCertificate.

sys/kern/sysv_sem.c in OpenBSD through 7.9 has a use-after-free allowing local privilege escalation to root. This is a context switch use-after-free after tsleep in sys_semget().

A flaw was found in the OpenSSH package. For each ping packet the SSH server receives, a pong packet is allocated in a memory buffer and stored in a queue of packages. It is only freed when the server/client key exchange has finished. A malicious client may keep sending such…

Multiple CRLF injection vulnerabilities in session.c in sshd in OpenSSH before 7.2p2 allow remote authenticated users to bypass intended shell-command restrictions via crafted X11 forwarding data, related to the (1) do_authenticated1 and (2) session_x11_req functions.

The SSH transport protocol with certain OpenSSH extensions, found in OpenSSH before 9.6 and other products, allows remote attackers to bypass integrity checks such that some packets are omitted (from the extension negotiation message), and a client and server may consequently…

sshd in OpenSSH 6.2 through 8.x before 8.8, when certain non-default configurations are used, allows privilege escalation because supplemental groups are not initialized as expected. Helper programs for AuthorizedKeysCommand and AuthorizedPrincipalsCommand may run with…

An issue was discovered in OpenSSH 7.9. Due to the scp implementation being derived from 1983 rcp, the server chooses which files/directories are sent to the client. However, the scp client only performs cursory validation of the object name returned (only directory traversal…

Use-after-free vulnerability in the mm_answer_pam_free_ctx function in monitor.c in sshd in OpenSSH before 7.0 on non-OpenBSD platforms might allow local users to gain privileges by leveraging control of the sshd uid to send an unexpectedly early MONITOR_REQ_PAM_FREE_CTX request.

The uipc system calls (uipc_syscalls.c) in OpenBSD 2.9 and 3.0 provide user mode return instead of versus rval kernel mode values to the fdrelease function, which allows local users to cause a denial of service and trigger a null dereference.

OpenSSH through 7.7 is prone to a user enumeration vulnerability due to not delaying bailout for an invalid authenticating user until after the packet containing the request has been fully parsed, related to auth2-gss.c, auth2-hostbased.c, and auth2-pubkey.c.

OpenNTPD before 6.0p1 does not validate the CN for HTTPS constraint requests, which allows remote attackers to bypass the man-in-the-middle mitigations via a crafted timestamp constraint with a valid certificate.

OpenBSD Kernel Multicast Routing Uninitialized Memory Information Disclosure Vulnerability. This vulnerability allows local attackers to disclose sensitive information on affected installations of OpenBSD Kernel. An attacker must first obtain the ability to execute…

In ssh-agent in OpenSSH before 9.6, certain destination constraints can be incompletely applied. When destination constraints are specified during addition of PKCS#11-hosted private keys, these constraints are only applied to the first key, even if a PKCS#11 token returns…

x509_constraints_parse_mailbox in lib/libcrypto/x509/x509_constraints.c in LibreSSL through 3.4.0 has a stack-based buffer over-read. When the input exceeds DOMAIN_PART_MAX_LEN, the buffer lacks '\0' termination.

tss_alloc in sys/arch/i386/i386/gdt.c in OpenBSD 6.2 and 6.3 has a Local Denial of Service (system crash) due to incorrect I/O port access control on the i386 architecture.

Integer overflow in the uvm_map_isavail function in uvm/uvm_map.c in OpenBSD 5.9 allows local users to cause a denial of service (kernel panic) via a crafted mmap call, which triggers the new mapping to overlap with an existing mapping.

OpenBSD 5.8 and 5.9 allows local users to cause a denial of service (NULL pointer dereference and panic) via a sysctl call with a path starting with 10,9.

OpenBSD 5.8 and 5.9 allows certain local users to cause a denial of service (kernel panic) by unmounting a filesystem with an open vnode on the mnt_vnodelist.

OpenBSD 5.8 and 5.9 allows local users to cause a denial of service (kernel panic) via a large size in a getdents system call.

thrsleep in kern/kern_synch.c in OpenBSD 5.8 and 5.9 allows local users to cause a denial of service (kernel panic) via a crafted value in the tsp parameter of the __thrsleep system call.

OpenBSD 5.8 and 5.9 allows local users to cause a denial of service (assertion failure and kernel panic) via a large ident value in a kevent system call.

The mmap extension __MAP_NOFAULT in OpenBSD 5.8 and 5.9 allows attackers to cause a denial of service (kernel panic and crash) via a large size value.

The ssh_packet_read_poll2 function in packet.c in OpenSSH before 7.1p2 allows remote attackers to cause a denial of service (out-of-bounds read and application crash) via crafted network traffic.

ssh-keysign.c in ssh-keysign in OpenSSH before 5.8p2 on certain platforms executes ssh-rand-helper with unintended open file descriptors, which allows local users to obtain sensitive key information via the ptrace system call.

tip on multiple BSD-based operating systems allows local users to cause a denial of service (execution prevention) by using flock() to lock the /var/log/acculog file.

sshd in OpenSSH before 10.4 does not always honor the minimum authentication delay.

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.

An issue was discovered in the kernel in OpenBSD 6.6. The WEP, WPA, WPA2, and WPA3 implementations treat fragmented frames as full frames. An adversary can abuse this to inject arbitrary network packets, independent of the network configuration.

Remotely observable behaviour in auth-gss2.c in OpenSSH through 7.8 could be used by remote attackers to detect existence of users on a target system when GSS2 is in use. NOTE: the discoverer states 'We understand that the OpenSSH developers do not want to treat such a username…

The process_open function in sftp-server.c in OpenSSH before 7.6 does not properly prevent write operations in readonly mode, which allows attackers to create zero-length files.

LibreSSL 2.5.1 to 2.5.3 lacks TLS certificate verification if SSL_get_verify_result is relied upon for a later check of a verification result, in a use case where a user-provided verification callback returns 1, as demonstrated by acceptance of invalid certificates by nginx.

The monitor component in sshd in OpenSSH before 7.0 on non-OpenBSD platforms accepts extraneous username data in MONITOR_REQ_PAM_INIT_CTX requests, which allows local users to conduct impersonation attacks by leveraging any SSH login access in conjunction with control of the…

openrsync through 0.5.0, as used in OpenBSD through 7.8 and on other platforms, allows a client to cause a server SIGSEGV by specifying a length of zero for block data, because the relationship between p->rem and p->len is not checked.