In sshd in OpenSSH before 10.0, the DisableForwarding directive does not adhere to the documentation stating that it disables X11 and agent forwarding.
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 packages, leading to an uncontrolled increase in memory consumption on the server side. Consequently, the server may become unavailable, resulting in a denial of service attack.
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 verifying the host key. For an attack to be considered successful, the attacker needs to manage to exhaust the client's memory resource first, turning the attack complexity high.
In OpenBSD 7.5 before errata 008 and OpenBSD 7.4 before errata 021,
avoid possible mbuf double free in NFS client and server implementation, do not use uninitialized variable in error handling of NFS server.
A security regression (CVE-2006-5051) was discovered in OpenSSH's server (sshd). There is a race condition which can lead sshd to handle some signals in an unsafe manner. An unauthenticated, remote attacker may be able to trigger it by failing to authenticate within a set time period.
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 low-privileged code on the target system in order to exploit this vulnerability.
The specific flaw exists within the implementation of multicast routing. The issue results from the lack of proper initialization of memory prior to accessing it. An attacker can leverage this in conjunction with other vulnerabilities to escalate privileges and execute arbitrary code in the context of the kernel.
. Was ZDI-CAN-14540.
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 low-privileged code on the target system in order to exploit this vulnerability.
The specific flaw exists within the implementation of multicast routing. The issue results from the lack of proper initialization of memory prior to accessing it. An attacker can leverage this in conjunction with other vulnerabilities to escalate privileges and execute arbitrary code in the context of the kernel.
. Was ZDI-CAN-16112.
NFS in a BSD derived codebase, as used in OpenBSD through 7.4 and FreeBSD through 14.0-RELEASE, allows remote attackers to execute arbitrary code via a bug that is unrelated to memory corruption.
OpenSSH through 9.6, 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 attacker-victim co-location in which the attacker has user privileges.