Jonathan Looney discovered that the Linux kernel default MSS is hard-coded to 48 bytes. This allows a remote peer to fragment TCP resend queues significantly more than if a larger MSS were enforced. A remote attacker could use this to cause a denial of service. This has been fixed in stable kernel releases 4.4.182, 4.9.182, 4.14.127, 4.19.52, 5.1.11, and is fixed in commits 967c05aee439e6e5d7d805e195b3a20ef5c433d6 and 5f3e2bf008c2221478101ee72f5cb4654b9fc363.

Jonathan Looney discovered that the TCP retransmission queue implementation in tcp_fragment in the Linux kernel could be fragmented when handling certain TCP Selective Acknowledgment (SACK) sequences. A remote attacker could use this to cause a denial of service. This has been fixed in stable kernel releases 4.4.182, 4.9.182, 4.14.127, 4.19.52, 5.1.11, and is fixed in commit f070ef2ac66716357066b683fb0baf55f8191a2e.

Jonathan Looney discovered that the TCP_SKB_CB(skb)->tcp_gso_segs value was subject to an integer overflow in the Linux kernel when handling TCP Selective Acknowledgments (SACKs). A remote attacker could use this to cause a denial of service. This has been fixed in stable kernel releases 4.4.182, 4.9.182, 4.14.127, 4.19.52, 5.1.11, and is fixed in commit 3b4929f65b0d8249f19a50245cd88ed1a2f78cff.

A heap address information leak while using L2CAP_GET_CONF_OPT was discovered in the Linux kernel before 5.1-rc1.

A flaw was found in the Linux kernel's NFS41+ subsystem. NFS41+ shares mounted in different network namespaces at the same time can make bc_svc_process() use wrong back-channel IDs and cause a use-after-free vulnerability. Thus a malicious container user can cause a host kernel memory corruption and a system panic. Due to the nature of the flaw, privilege escalation cannot be fully ruled out.

In the Linux kernel before version 4.12, Kerberos 5 tickets decoded when using the RXRPC keys incorrectly assumes the size of a field. This could lead to the size-remaining variable wrapping and the data pointer going over the end of the buffer. This could possibly lead to memory corruption and possible privilege escalation.

The memory resource controller (aka memcg) in the Linux kernel allows local users to cause a denial of service (deadlock) by spawning new processes within a memory-constrained cgroup.

A flaw was found in the hugetlb_mcopy_atomic_pte function in mm/hugetlb.c in the Linux kernel before 4.13.12. A lack of size check could cause a denial of service (BUG).

A flaw was found in the hugetlb_mcopy_atomic_pte function in mm/hugetlb.c in the Linux kernel before 4.13. A superfluous implicit page unlock for VM_SHARED hugetlbfs mapping could trigger a local denial of service (BUG).

The Linux kernel, as used in Red Hat Enterprise Linux 7, kernel-rt, and Enterprise MRG 2 and when booted with UEFI Secure Boot enabled, allows local users to bypass intended securelevel/secureboot restrictions by leveraging improper handling of secure_boot flag across kexec reboot.

Race condition in the kernel in Red Hat Enterprise Linux 7, kernel-rt and Red Hat Enterprise MRG 2, when the nfnetlink_log module is loaded, allows local users to cause a denial of service (panic) by creating netlink sockets.

The Linux kernel, as used in Red Hat Enterprise Linux 7.2 and Red Hat Enterprise MRG 2 and when booted with UEFI Secure Boot enabled, allows local users to bypass intended Secure Boot restrictions and execute untrusted code by appending ACPI tables to the initrd.

The key_reject_and_link function in security/keys/key.c in the Linux kernel through 4.6.3 does not ensure that a certain data structure is initialized, which allows local users to cause a denial of service (system crash) via vectors involving a crafted keyctl request2 command.

The futex_requeue function in kernel/futex.c in the Linux kernel through 3.14.5 does not ensure that calls have two different futex addresses, which allows local users to gain privileges via a crafted FUTEX_REQUEUE command that facilitates unsafe waiter modification.

The Linux kernel through 3.14.5 does not properly consider the presence of hugetlb entries, which allows local users to cause a denial of service (memory corruption or system crash) by accessing certain memory locations, as demonstrated by triggering a race condition via numa_maps read operations during hugepage migration, related to fs/proc/task_mmu.c and mm/mempolicy.c.

kernel/auditsc.c in the Linux kernel through 3.14.5, when CONFIG_AUDITSYSCALL is enabled with certain syscall rules, allows local users to obtain potentially sensitive single-bit values from kernel memory or cause a denial of service (OOPS) via a large value of a syscall number.

Multiple format string vulnerabilities in Condor 7.2.0 through 7.6.4, and possibly certain 7.7.x versions, as used in Red Hat MRG Grid and possibly other products, allow local users to cause a denial of service (condor_schedd daemon and failure to launch jobs) and possibly execute arbitrary code via format string specifiers in (1) the reason for a hold for a job that uses an XML user log, (2) the filename of a file to be transferred, and possibly other unspecified vectors.

The policy definition evaluator in Condor 7.5.4, 8.0.0, and earlier does not properly handle attributes in a (1) PREEMPT, (2) SUSPEND, (3) CONTINUE, (4) WANT_VACATE, or (5) KILL policy that evaluate to an Unconfigured, Undefined, or Error state, which allows remote authenticated users to cause a denial of service (condor_startd exit) via a crafted job.

Off-by-one error in the get_prng_bytes function in crypto/ansi_cprng.c in the Linux kernel through 3.11.4 makes it easier for context-dependent attackers to defeat cryptographic protection mechanisms via multiple requests for small amounts of data, leading to improper management of the state of the consumed data.

The Python client in Apache Qpid before 2.2 does not verify that the server hostname matches a domain name in the subject's Common Name (CN) or subjectAltName field of the X.509 certificate, which allows man-in-the-middle attackers to spoof SSL servers via an arbitrary valid certificate.