William Liu and Jamie Hill-Daniel discovered that the file system context functionality in the Linux kernel contained an integer underflow vulnerability, leading to an out-of-bounds write. A local attacker could use this to cause a denial of service (system crash) or execute arbitrary code.

It was discovered that the eBPF implementation in the Linux kernel did not properly validate the memory size of certain ring buffer operation arguments. A local attacker could use this to cause a denial of service (system crash) or possibly execute arbitrary code.

It was discovered that HTMLDOC improperly handled malformed URIs from an input html file. An attacker could use this to cause a denial of service.

Jan-Niklas Sohn discovered that the X.Org X Server incorrectly handled certain inputs. An attacker could use this issue to cause the server to crash, resulting in a denial of service, or possibly execute arbitrary code and escalate privileges.

It was discovered that BusyBox incorrectly handled certain malformed gzip archives. If a user or automated system were tricked into processing a specially crafted gzip archive, a remote attacker could use this issue to cause BusyBox to crash, resulting in a denial of service, or possibly execute arbitrary code. (CVE-2021-28831) It was discovered that BusyBox incorrectly handled certain malformed LZMA archives. If a user or automated system were tricked into processing a specially crafted LZMA archive, a remote attacker could use this issue to cause BusyBox to crash, resulting in a denial of service, or possibly leak sensitive information. (CVE-2021-42374) Vera Mens, Uri Katz, Tal Keren, Sharon Brizinov, and Shachar Menashe discovered that BusyBox incorrectly handled certain awk patterns. If a user or automated system were tricked into processing a specially crafted awk pattern, a remote attacker could use this issue to cause BusyBox to crash, resulting in a denial of service, or possibly execute arbitrary code. (CVE-2021-42378, CVE-2021-42379, CVE-2021-42380, CVE-2021-42381, CVE-2021-42382, CVE-2021-42384, CVE-2021-42385, CVE-2021-42386)

Ilja Van Sprundel discovered that the SCTP implementation in the Linux kernel did not properly perform size validations on incoming packets in some situations. An attacker could possibly use this to expose sensitive information (kernel memory). (CVE-2021-3655) It was discovered that the AMD Cryptographic Coprocessor (CCP) driver in the Linux kernel did not properly deallocate memory in some error conditions. A local attacker could use this to cause a denial of service (memory exhaustion). (CVE-2021-3744, CVE-2021-3764) It was discovered that the Aspeed Low Pin Count (LPC) Bus Controller implementation in the Linux kernel did not properly perform boundary checks in some situations, allowing out-of-bounds write access. A local attacker could use this to cause a denial of service (system crash) or possibly execute arbitrary code. In Ubuntu, this issue only affected systems running armhf kernels. (CVE-2021-42252)

It was discovered that Vim incorrectly handled permissions on the .swp file. A local attacker could possibly use this issue to obtain sensitive information. This issue only affected Ubuntu 14.04 ESM. (CVE-2017-17087) It was discovered that Vim incorrectly handled restricted mode. A local attacker could possibly use this issue to bypass restricted mode and execute arbitrary commands. Note: This update only makes executing shell commands more difficult. Restricted mode should not be considered a complete security measure. This issue only affected Ubuntu 14.04 ESM. (CVE-2019-20807) Brian Carpenter discovered that vim incorrectly handled memory when opening certain files. If a user was tricked into opening a specially crafted file, a remote attacker could crash the application, leading to a denial of service, or possible execute arbitrary code with user privileges. This issue only affected Ubuntu 20.04 LTS, Ubuntu 21.04 and Ubuntu 21.10. (CVE-2021-3872) It was discovered that vim incorrectly handled memory when opening certain files. If a user was tricked into opening a specially crafted file, a remote attacker could crash the application, leading to a denial of service, or possible execute arbitrary code with user privileges. (CVE-2021-3903) It was discovered that vim incorrectly handled memory when opening certain files. If a user was tricked into opening a specially crafted file, a remote attacker could crash the application, leading to a denial of service, or possible execute arbitrary code with user privileges. (CVE-2021-3927) It was discovered that vim incorrectly handled memory when opening certain files. If a user was tricked into opening a specially crafted file, a remote attacker could crash the application, leading to a denial of service, or possible execute arbitrary code with user privileges. (CVE-2021-3928)

Stefan Metzmacher discovered that Samba incorrectly handled SMB1 client connections. A remote attacker could possibly use this issue to downgrade connections to plaintext authentication. (CVE-2016-2124) Andrew Bartlett discovered that Samba incorrectly mapping domain users to local users. An authenticated attacker could possibly use this issue to become root on domain members. (CVE-2020-25717) Andrew Bartlett discovered that Samba did not correctly sandbox Kerberos tickets issues by an RODC. An RODC could print administrator tickets, contrary to expectations. (CVE-2020-25718) Andrew Bartlett discovered that Samba incorrectly handled Kerberos tickets. Delegated administrators could possibly use this issue to impersonate accounts, leading to total domain compromise. (CVE-2020-25719) Andrew Bartlett discovered that Samba did not provide stable AD identifiers to Kerberos acceptors. (CVE-2020-25721) Andrew Bartlett discovered that Samba did not properly check sensitive attributes. An authenticated attacker could possibly use this issue to escalate privileges. (CVE-2020-25722) Stefan Metzmacher discovered that Samba incorrectly handled certain large DCE/RPC requests. A remote attacker could possibly use this issue to bypass signature requirements. (CVE-2021-23192) William Ross discovered that Samba incorrectly handled memory. A remote attacker could use this issue to cause Samba to crash, resulting in a denial of service, or possibly escalate privileges. (CVE-2021-3738) Joseph Sutton discovered that Samba incorrectly handled certain TGS requests. An authenticated attacker could possibly use this issue to cause Samba to crash, resulting in a denial of service. (CVE-2021-3671) The fix for CVE-2020-25717 results in possible behaviour changes that could affect certain environments. Please see the upstream advisory for more information: https://www.samba.org/samba/security/CVE-2020-25717.html

It was discovered that the Linux kernel did not properly account for the memory usage of certain IPC objects. A local attacker could use this to cause a denial of service (memory exhaustion).

Maverick Chung and Qiaoyi Fang discovered that cpio incorrectly handled certain pattern files. A remote attacker could use this issue to cause cpio to crash, resulting in a denial of service, or possibly execute arbitrary code.

John Ouyang discovered that OpenSSL incorrectly handled decrypting SM2 data. A remote attacker could use this issue to cause applications using OpenSSL to crash, resulting in a denial of service, or possibly change application behaviour. (CVE-2021-3711) Ingo Schwarze discovered that OpenSSL incorrectly handled certain ASN.1 strings. A remote attacker could use this issue to cause OpenSSL to crash, resulting in a denial of service, or possibly obtain sensitive information. (CVE-2021-3712)

It was discovered that the virtual file system implementation in the Linux kernel contained an unsigned to signed integer conversion error. A local attacker could use this to cause a denial of service (system crash) or execute arbitrary code.

Lei Sun discovered that QEMU incorrectly handled certain MMIO operations. An attacker inside the guest could possibly use this issue to cause QEMU to crash, resulting in a denial of service. (CVE-2020-15469) Wenxiang Qian discovered that QEMU incorrectly handled certain ATAPI commands. An attacker inside the guest could possibly use this issue to cause QEMU to crash, resulting in a denial of service. This issue only affected Ubuntu 21.04. (CVE-2020-29443) Cheolwoo Myung discovered that QEMU incorrectly handled SCSI device emulation. An attacker inside the guest could possibly use this issue to cause QEMU to crash, resulting in a denial of service. (CVE-2020-35504, CVE-2020-35505, CVE-2021-3392) Alex Xu discovered that QEMU incorrectly handled the virtio-fs shared file system daemon. An attacker inside the guest could possibly use this issue to read and write to host devices. This issue only affected Ubuntu 20.10. (CVE-2020-35517) It was discovered that QEMU incorrectly handled ARM Generic Interrupt Controller emulation. An attacker inside the guest could possibly use this issue to cause QEMU to crash, resulting in a denial of service. This issue only affected Ubuntu 18.04 LTS, Ubuntu 20.04 LTS, and Ubuntu 20.10. (CVE-2021-20221) Alexander Bulekov, Cheolwoo Myung, Sergej Schumilo, Cornelius Aschermann, and Simon Werner discovered that QEMU incorrectly handled e1000 device emulation. An attacker inside the guest could possibly use this issue to cause QEMU to hang, resulting in a denial of service. This issue only affected Ubuntu 18.04 LTS, Ubuntu 20.04 LTS, and Ubuntu 20.10. (CVE-2021-20257) It was discovered that QEMU incorrectly handled SDHCI controller emulation. An attacker inside the guest could use this issue to cause QEMU to crash, resulting in a denial of service, or possibly execute arbitrary code. In the default installation, when QEMU is used in combination with libvirt, attackers would be isolated by the libvirt AppArmor profile. (CVE-2021-3409) It was discovered that QEMU incorrectly handled certain NIC emulation devices. An attacker inside the guest could possibly use this issue to cause QEMU to hang or crash, resulting in a denial of service. This issue only affected Ubuntu 18.04 LTS, Ubuntu 20.04 LTS, and Ubuntu 20.10. (CVE-2021-3416) Remy Noel discovered that QEMU incorrectly handled the USB redirector device. An attacker inside the guest could possibly use this issue to cause QEMU to consume resources, resulting in a denial of service. (CVE-2021-3527) It was discovered that QEMU incorrectly handled the virtio vhost-user GPU device. An attacker inside the guest could possibly use this issue to cause QEMU to consume resources, leading to a denial of service. This issue only affected Ubuntu 20.04 LTS, Ubuntu 20.10, and Ubuntu 21.04. (CVE-2021-3544) It was discovered that QEMU incorrectly handled the virtio vhost-user GPU device. An attacker inside the guest could possibly use this issue to obtain sensitive host information. This issue only affected Ubuntu 20.04 LTS, Ubuntu 20.10, and Ubuntu 21.04. (CVE-2021-3545) It was discovered that QEMU incorrectly handled the virtio vhost-user GPU device. An attacker inside the guest could use this issue to cause QEMU to crash, resulting in a denial of service, or possibly execute arbitrary code. In the default installation, when QEMU is used in combination with libvirt, attackers would be isolated by the libvirt AppArmor profile. This issue only affected Ubuntu 20.04 LTS, Ubuntu 20.10, and Ubuntu 21.04. (CVE-2021-3546) It was discovered that QEMU incorrectly handled the PVRDMA device. An attacker inside the guest could use this issue to cause QEMU to crash, resulting in a denial of service, or possibly execute arbitrary code. In the default installation, when QEMU is used in combination with libvirt, attackers would be isolated by the libvirt AppArmor profile. This issue only affected Ubuntu 20.04 LTS, Ubuntu 20.10, and Ubuntu 21.04. (CVE-2021-3582, CVE-2021-3607, CVE-2021-3608) It was discovered that QEMU SLiRP networking incorrectly handled certain udp packets. An attacker inside a guest could possibly use this issue to leak sensitive information from the host. (CVE-2021-3592, CVE-2021-3593, CVE-2021-3594, CVE-2021-3595)

Qiuhao Li discovered that libslirp incorrectly handled certain header data lengths. An attacker inside a guest could possibly use this issue to leak sensitive information from the host. This issue only affected Ubuntu 20.04 LTS and Ubuntu 20.10. (CVE-2020-29129, CVE-2020-29130) It was discovered that libslirp incorrectly handled certain udp packets. An attacker inside a guest could possibly use this issue to leak sensitive information from the host. (CVE-2021-3592, CVE-2021-3593, CVE-2021-3594, CVE-2021-3595)

Joshua Rogers discovered that Squid incorrectly handled requests with the urn: scheme. A remote attacker could possibly use this issue to cause Squid to consume resources, leading to a denial of service. (CVE-2021-28651) Joshua Rogers discovered that Squid incorrectly handled requests to the Cache Manager API. A remote attacker with access privileges could possibly use this issue to cause Squid to consume resources, leading to a denial of service. This issue was only addressed in Ubuntu 20.04 LTS, Ubuntu 20.10, and Ubuntu 21.04. (CVE-2021-28652) Joshua Rogers discovered that Squid incorrectly handled certain response headers. A remote attacker could possibly use this issue to cause Squid to crash, resulting in a denial of service. This issue was only affected Ubuntu 20.04 LTS, Ubuntu 20.10, and Ubuntu 21.04. (CVE-2021-28662) Joshua Rogers discovered that Squid incorrectly handled range request processing. A remote attacker could possibly use this issue to cause Squid to crash, resulting in a denial of service. (CVE-2021-31806, CVE-2021-31807, CVE-2021-31808) Joshua Rogers discovered that Squid incorrectly handled certain HTTP responses. A remote attacker could possibly use this issue to cause Squid to crash, resulting in a denial of service. (CVE-2021-33620)

Etienne Champetier discovered that runC incorrectly checked mount targets. An attacker with a malicious container image could possibly mount the host filesystem into the container and escalate privileges.

Zhihong Tian and Hui Lu found that XStream was vulnerable to remote code execution. A remote attacker could run arbitrary shell commands by manipulating the processed input stream. This issue affected only affected Ubuntu 20.10. (CVE-2020-26217) It was discovered that XStream was vulnerable to server-side forgery attacks. A remote attacker could request data from internal resources that are not publicly available only by manipulating the processed input stream. This issue only affected Ubuntu 20.10. (CVE-2020-26258) It was discovered that XStream was vulnerable to arbitrary file deletion on the local host. A remote attacker could use this to delete arbitrary known files on the host as long as the executing process had sufficient rights only by manipulating the processed input stream. This issue only affected Ubuntu 20.10. (CVE-2020-26259) It was discovered that XStream was vulnerable to denial of service, arbitrary code execution, arbitrary file deletion and server-side forgery attacks. A remote attacker could cause any of those issues by manipulating the processed input stream. (CVE-2021-21341, CVE-2021-21342, CVE-2021-21343 CVE-2021-21344, CVE-2021-21345, CVE-2021-21346, CVE-2021-21347, CVE-2021-21348, CVE-2021-21349, CVE-2021-21350, CVE-2021-21351)

It was discovered that OpenVPN incorrectly handled certain data channel v2 packets. A remote attacker could possibly use this issue to inject packets using a victim's peer-id. This issue only affected Ubuntu 18.04 LTS and Ubuntu 20.04 LTS. (CVE-2020-11810) It was discovered that OpenVPN incorrectly handled deferred authentication. When a server is configured to use deferred authentication, a remote attacker could possibly use this issue to bypass authentication and access control channel data. (CVE-2020-15078)