A use after free issue was found in the way Linux kernel's KVM hypervisor implements its device control API. While creating a device via kvmioctlcreatedevice(), device holds a reference to a VM object, latter this reference is transferred to caller's file descriptor table. If such file descriptor was to be closed, reference count to the VM object could become zero, potentially leading to use-after-free issue latter.

A user/process could use this flaw to crash the guest VM resulting in DoS issue OR potentially gain privileged access to a system.

Upstream patch: --------------- -> https://git.kernel.org/linus/cfa39381173d5f969daf43582c95ad679189cbc9

Reference: ---------- -> https://www.openwall.com/lists/oss-security/2019/02/18/2

A flaw named SegmentSmack was found in the way the Linux kernel handled specially crafted TCP packets. A remote attacker could use this flaw to trigger time and calculation expensive calls to tcpcollapseofoqueue() and tcppruneofoqueue() functions by sending specially modified packets within ongoing TCP sessions which could lead to a CPU saturation and hence a denial of service on the system. Maintaining the denial of service condition requires continuous two-way TCP sessions to a reachable open port, thus the attacks cannot be performed using spoofed IP addresses.

An integer overflow flaw was found in the way the Linux kernel's networking subsystem processed TCP Selective Acknowledgment (SACK) segments. While processing SACK segments, the Linux kernel's socket buffer (SKB) data structure becomes fragmented. Each fragment is about TCP maximum segment size (MSS) bytes. To efficiently process SACK blocks, the Linux kernel merges multiple fragmented SKBs into one, potentially overflowing the variable holding the number of segments. A remote attacker could use this flaw to crash the Linux kernel by sending a crafted sequence of SACK segments on a TCP connection with small value of TCP MSS, resulting in a denial of service (DoS).

By design, BIND is intended to limit the number of TCP clients that can be connected at any given time. The number of allowed connections is a tunable parameter which, if unset, defaults to a conservative value for most servers. Unfortunately, the code which was intended to limit the number of simultaneous connections contained an error which could be exploited to grow the number of simultaneous connections beyond this limit. Versions affected: BIND 9.9.0 -> 9.10.8-P1, 9.11.0 -> 9.11.6, 9.12.0 -> 9.12.4, 9.14.0. BIND 9 Supported Preview Edition versions 9.9.3-S1 -> 9.11.5-S3, and 9.11.5-S5. Versions 9.13.0 -> 9.13.7 of the 9.13 development branch are also affected. Versions prior to BIND 9.9.0 have not been evaluated for vulnerability to CVE-2018-5743.

An excessive resource consumption flaw was found in the way the Linux kernel's networking subsystem processed TCP Selective Acknowledgment (SACK) segments. While processing SACK segments, the Linux kernel's socket buffer (SKB) data structure becomes fragmented, which leads to increased resource utilization to traverse and process these fragments as further SACK segments are received on the same TCP connection. A remote attacker could use this flaw to cause a denial of service (DoS) by sending a crafted sequence of SACK segments on a TCP connection.

On F5 BIG-IP 14.0.0, 13.0.0-13.1.0, 12.1.0-12.1.3, or 11.5.1-11.6.3 specifically crafted HTTP responses, when processed by a Virtual Server with an associated QoE profile that has Video enabled, may cause TMM to incorrectly buffer response data causing the TMM to restart resulting in a Denial of Service.

On BIG-IP 14.0.x, 13.x, 12.x, and 11.x, Enterprise Manager 3.1.1, BIG-IQ 6.x, 5.x, and 4.x, and iWorkflow 2.x, the passphrases for SNMPv3 users and trap destinations that are used for authentication and privacy are not handled by the BIG-IP system Secure Vault feature; they are written in the clear to the various configuration files.

On versions 14.1.0-14.1.0.5, 14.0.0-14.0.0.4, 13.0.0-13.1.2, 12.1.0-12.1.4.1, and 11.5.2-11.6.4, an attacker sending specifically crafted DHCPv6 requests through a BIG-IP virtual server configured with a DHCPv6 profile may be able to cause the TMM process to produce a core file.

On BIG-IP 14.0.0-14.1.0.5, 13.0.0-13.1.2, 12.1.0-12.1.4.1, 11.5.2-11.6.4, FTP traffic passing through a Virtual Server with both an active FTP profile associated and connection mirroring configured may lead to a TMM crash causing the configured HA action to be taken.