A buffer overflow flaw was found, in versions from 2.6.34 to 5.2.x, in the way Linux kernel's vhost functionality that translates virtqueue buffers to IOVs, logged the buffer descriptors during migration. A privileged guest user able to pass descriptors with invalid length to the host when migration is underway, could use this flaw to increase their privileges on the host.

When encrypting with a block cipher, if a call to NSC_EncryptUpdate was made with data smaller than the block size, a small out of bounds write could occur. This could have caused heap corruption and a potentially exploitable crash. This vulnerability affects Thunderbird < 68.3, Firefox ESR < 68.3, and Firefox < 71.

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 double-free can happen in idr_remove_all() in lib/idr.c in the Linux kernel 2.6 branch. An unprivileged local attacker can use this flaw for a privilege escalation or for a system crash and a denial of service (DoS).

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.

While investigating bug PROTON-2014, we discovered that under some circumstances Apache Qpid Proton versions 0.9 to 0.27.0 (C library and its language bindings) can connect to a peer anonymously using TLS *even when configured to verify the peer certificate* while used with OpenSSL versions before 1.1.0. This means that an undetected man in the middle attack could be constructed if an attacker can arrange to intercept TLS traffic.

A denial of service flaw was found in the way BIND handled DNSSEC validation. A remote attacker could use this flaw to make named exit unexpectedly with an assertion failure via a specially crafted DNS response.

BIND was improperly sequencing cleanup operations on upstream recursion fetch contexts, leading in some cases to a use-after-free error that can trigger an assertion failure and crash in named. Affects BIND 9.0.0 to 9.8.x, 9.9.0 to 9.9.11, 9.10.0 to 9.10.6, 9.11.0 to 9.11.2, 9.9.3-S1 to 9.9.11-S1, 9.10.5-S1 to 9.10.6-S1, 9.12.0a1 to 9.12.0rc1.

Mistaken assumptions about the ordering of records in the answer section of a response containing CNAME or DNAME resource records could lead to a situation in which named would exit with an assertion failure when processing a response in which records occurred in an unusual order. Affects BIND 9.9.9-P6, 9.9.10b1->9.9.10rc1, 9.10.4-P6, 9.10.5b1->9.10.5rc1, 9.11.0-P3, 9.11.1b1->9.11.1rc1, and 9.9.9-S8.

In PolicyKit (aka polkit) 0.115, the "start time" protection mechanism can be bypassed because fork() is not atomic, and therefore authorization decisions are improperly cached. This is related to lack of uid checking in polkitbackend/polkitbackendinteractiveauthority.c.