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 Apache Log4j 2 was vulnerable to remote code execution (RCE) attack when configured to use a JDBC Appender with a JNDI LDAP data source URI. A remote attacker could possibly use this issue to cause a crash, leading to a denial of service. (CVE-2021-44832) Hideki Okamoto and Guy Lederfein discovered that Apache Log4j 2 did not protect against infinite recursion in lookup evaluation. A remote attacker could possibly use this issue to cause Apache Log4j 2 to crash, leading to a denial of service. This issue only affected Ubuntu 18.04 LTS. (CVE-2021-45105)

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.

Nadav Amit discovered that the hugetlb implementation in the Linux kernel did not perform TLB flushes under certain conditions. A local attacker could use this to leak or alter data from other processes that use huge pages. (CVE-2021-4002) It was discovered that a race condition existed in the overlay file system implementation in the Linux kernel. A local attacker could use this to cause a denial of service (system crash). (CVE-2021-20321) It was discovered that the NFC subsystem in the Linux kernel contained a use-after-free vulnerability in its NFC Controller Interface (NCI) implementation. A local attacker could possibly use this to cause a denial of service (system crash) or execute arbitrary code. (CVE-2021-3760) It was discovered that an integer overflow could be triggered in the eBPF implementation in the Linux kernel when preallocating objects for stack maps. A privileged local attacker could use this to cause a denial of service or possibly execute arbitrary code. (CVE-2021-41864) It was discovered that the KVM implementation for POWER8 processors in the Linux kernel did not properly keep track if a wakeup event could be resolved by a guest. An attacker in a guest VM could possibly use this to cause a denial of service (host OS crash). (CVE-2021-43056) It was discovered that the TIPC Protocol implementation in the Linux kernel did not properly validate MSGCRYPTO messages in some situations. An attacker could use this to cause a denial of service (system crash) or possibly execute arbitrary code. (CVE-2021-43267) It was discovered that the ISDN CAPI implementation in the Linux kernel contained a race condition in certain situations that could trigger an array out-of-bounds bug. A privileged local attacker could possibly use this to cause a denial of service or execute arbitrary code. (CVE-2021-43389)

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 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).

It was discovered that a race condition existed in the Atheros Ath9k WiFi driver in the Linux kernel. An attacker could possibly use this to expose sensitive information (WiFi network traffic). (CVE-2020-3702) Alois Wohlschlager discovered that the overlay file system in the Linux kernel did not restrict private clones in some situations. An attacker could use this to expose sensitive information. (CVE-2021-3732) It was discovered that the btrfs file system in the Linux kernel did not properly handle removing a non-existent device id. An attacker with CAPSYSADMIN could use this to cause a denial of service. (CVE-2021-3739) It was discovered that the Qualcomm IPC Router protocol implementation in the Linux kernel did not properly validate metadata in some situations. A local attacker could use this to cause a denial of service (system crash) or expose sensitive information. (CVE-2021-3743) It was discovered that the virtual terminal (vt) device implementation in the Linux kernel contained a race condition in its ioctl handling that led to an out-of-bounds read vulnerability. A local attacker could possibly use this to expose sensitive information. (CVE-2021-3753) It was discovered that the BPF subsystem in the Linux kernel contained an integer overflow in its hash table implementation. A local attacker could use this to cause a denial of service (system crash) or possibly execute arbitrary code. (CVE-2021-38166) It was discovered that the ext4 file system in the Linux kernel contained a race condition when writing xattrs to an inode. A local attacker could use this to cause a denial of service or possibly gain administrative privileges. (CVE-2021-40490) It was discovered that the 6pack network protocol driver in the Linux kernel did not properly perform validation checks. A privileged attacker could use this to cause a denial of service (system crash) or execute arbitrary code. (CVE-2021-42008)

Valentina Palmiotti discovered that the iouring subsystem in the Linux kernel could be coerced to free adjacent memory. A local attacker could use this to execute arbitrary code. (CVE-2021-41073) Ofek Kirzner, Adam Morrison, Benedict Schlueter, and Piotr Krysiuk discovered that the BPF verifier in the Linux kernel missed possible mispredicted branches due to type confusion, allowing a side-channel attack. An attacker could use this to expose sensitive information. (CVE-2021-33624) Benedict Schlueter discovered that the BPF subsystem in the Linux kernel did not properly protect against Speculative Store Bypass (SSB) side- channel attacks in some situations. A local attacker could possibly use this to expose sensitive information. (CVE-2021-34556) Piotr Krysiuk discovered that the BPF subsystem in the Linux kernel did not properly protect against Speculative Store Bypass (SSB) side-channel attacks in some situations. A local attacker could possibly use this to expose sensitive information. (CVE-2021-35477) It was discovered that the tracing subsystem in the Linux kernel did not properly keep track of per-cpu ring buffer state. A privileged attacker could use this to cause a denial of service. (CVE-2021-3679) It was discovered that the Option USB High Speed Mobile device driver in the Linux kernel did not properly handle error conditions. A physically proximate attacker could use this to cause a denial of service (system crash) or possibly execute arbitrary code. (CVE-2021-37159) Alexey Kardashevskiy discovered that the KVM implementation for PowerPC systems in the Linux kernel did not properly validate RTAS arguments in some situations. An attacker in a guest vm could use this to cause a denial of service (host OS crash) or possibly execute arbitrary code. (CVE-2021-37576) It was discovered that the Virtio console implementation in the Linux kernel did not properly validate input lengths in some situations. A local attacker could possibly use this to cause a denial of service (system crash). (CVE-2021-38160) Michael Wakabayashi discovered that the NFSv4 client implementation in the Linux kernel did not properly order connection setup operations. An attacker controlling a remote NFS server could use this to cause a denial of service on the client. (CVE-2021-38199) It was discovered that the Sun RPC implementation in the Linux kernel contained an out-of-bounds access error. A remote attacker could possibly use this to cause a denial of service (system crash). (CVE-2021-38201) It was discovered that the MAX-3421 host USB device driver in the Linux kernel did not properly handle device removal events. A physically proximate attacker could use this to cause a denial of service (system crash). (CVE-2021-38204) It was discovered that the Xilinx 10/100 Ethernet Lite device driver in the Linux kernel could report pointer addresses in some situations. An attacker could use this information to ease the exploitation of another vulnerability. (CVE-2021-38205)

Valentina Palmiotti discovered that the iouring subsystem in the Linux kernel could be coerced to free adjacent memory. A local attacker could use this to execute arbitrary code. (CVE-2021-41073) Ofek Kirzner, Adam Morrison, Benedict Schlueter, and Piotr Krysiuk discovered that the BPF verifier in the Linux kernel missed possible mispredicted branches due to type confusion, allowing a side-channel attack. An attacker could use this to expose sensitive information. (CVE-2021-33624) Benedict Schlueter discovered that the BPF subsystem in the Linux kernel did not properly protect against Speculative Store Bypass (SSB) side- channel attacks in some situations. A local attacker could possibly use this to expose sensitive information. (CVE-2021-34556) Piotr Krysiuk discovered that the BPF subsystem in the Linux kernel did not properly protect against Speculative Store Bypass (SSB) side-channel attacks in some situations. A local attacker could possibly use this to expose sensitive information. (CVE-2021-35477) It was discovered that the tracing subsystem in the Linux kernel did not properly keep track of per-cpu ring buffer state. A privileged attacker could use this to cause a denial of service. (CVE-2021-3679) It was discovered that the Option USB High Speed Mobile device driver in the Linux kernel did not properly handle error conditions. A physically proximate attacker could use this to cause a denial of service (system crash) or possibly execute arbitrary code. (CVE-2021-37159) Alexey Kardashevskiy discovered that the KVM implementation for PowerPC systems in the Linux kernel did not properly validate RTAS arguments in some situations. An attacker in a guest vm could use this to cause a denial of service (host OS crash) or possibly execute arbitrary code. (CVE-2021-37576) It was discovered that the Virtio console implementation in the Linux kernel did not properly validate input lengths in some situations. A local attacker could possibly use this to cause a denial of service (system crash). (CVE-2021-38160) Michael Wakabayashi discovered that the NFSv4 client implementation in the Linux kernel did not properly order connection setup operations. An attacker controlling a remote NFS server could use this to cause a denial of service on the client. (CVE-2021-38199) It was discovered that the Sun RPC implementation in the Linux kernel contained an out-of-bounds access error. A remote attacker could possibly use this to cause a denial of service (system crash). (CVE-2021-38201) It was discovered that the MAX-3421 host USB device driver in the Linux kernel did not properly handle device removal events. A physically proximate attacker could use this to cause a denial of service (system crash). (CVE-2021-38204) It was discovered that the Xilinx 10/100 Ethernet Lite device driver in the Linux kernel could report pointer addresses in some situations. An attacker could use this information to ease the exploitation of another vulnerability. (CVE-2021-38205)

It was discovered that EDK II incorrectly handled input validation in MdeModulePkg. A local user could possibly use this issue to cause EDK II to crash, resulting in a denial of service, obtain sensitive information or execute arbitrary code. (CVE-2019-11098) Paul Kehrer discovered that OpenSSL used in EDK II incorrectly handled certain input lengths in EVP functions. An attacker could possibly use this issue to cause EDK II to crash, resulting in a denial of service. (CVE-2021-23840) Ingo Schwarze discovered that OpenSSL used in EDK II incorrectly handled certain ASN.1 strings. An attacker could use this issue to cause EDK II to crash, resulting in a denial of service, or possibly obtain sensitive information. (CVE-2021-3712) It was discovered that EDK II incorrectly decoded certain strings. A remote attacker could use this issue to cause EDK II to crash, resulting in a denial of service, or possibly execute arbitrary code. (CVE-2021-38575)

Maxim Levitsky and Paolo Bonzini discovered that the KVM hypervisor implementation for AMD processors in the Linux kernel allowed a guest VM to disable restrictions on VMLOAD/VMSAVE in a nested guest. An attacker in a guest VM could use this to read or write portions of the host's physical memory. (CVE-2021-3656) Maxim Levitsky discovered that the KVM hypervisor implementation for AMD processors in the Linux kernel did not properly prevent a guest VM from enabling AVIC in nested guest VMs. An attacker in a guest VM could use this to write to portions of the host's physical memory. (CVE-2021-3653) It was discovered that the Linux kernel did not properly enforce certain types of entries in the Secure Boot Forbidden Signature Database (aka dbx) protection mechanism. An attacker could use this to bypass UEFI Secure Boot restrictions. (CVE-2020-26541) It was discovered that the KVM hypervisor implementation in the Linux kernel did not properly perform reference counting in some situations, leading to a use-after-free vulnerability. An attacker who could start and control a VM could possibly use this to expose sensitive information or execute arbitrary code. (CVE-2021-22543) Norbert Slusarek discovered that the CAN broadcast manger (bcm) protocol implementation in the Linux kernel did not properly initialize memory in some situations. A local attacker could use this to expose sensitive information (kernel memory). (CVE-2021-34693) Murray McAllister discovered that the joystick device interface in the Linux kernel did not properly validate data passed via an ioctl(). A local attacker could use this to cause a denial of service (system crash) or possibly execute arbitrary code on systems with a joystick device registered. (CVE-2021-3612) It was discovered that the KVM hypervisor implementation in the Linux kernel did not properly compute the access permissions for shadow pages in some situations. A local attacker could use this to cause a denial of service. (CVE-2021-38198) It was discovered that the perf subsystem in the Linux kernel for the PowerPC architecture contained a null pointer dereference in some situations. An attacker could use this to cause a denial of service (system crash). (CVE-2021-38200) Ben Greear discovered that the mac80211 subsystem in the Linux kernel contained a null pointer dereference in some situations. A physically proximate attacker could possibly use this to cause a denial of service (system crash). (CVE-2021-38206) It was discovered that the Xilinx LL TEMAC device driver in the Linux kernel did not properly calculate the number of buffers to be used in certain situations. A remote attacker could use this to cause a denial of service (system crash). (CVE-2021-38207)

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 bluetooth subsystem in the Linux kernel did not properly perform access control. An authenticated attacker could possibly use this to expose sensitive information. (CVE-2020-26558, CVE-2021-0129) Michael Brown discovered that the Xen netback driver in the Linux kernel did not properly handle malformed packets from a network PV frontend, leading to a use-after-free vulnerability. An attacker in a guest VM could use this to cause a denial of service or possibly execute arbitrary code. (CVE-2021-28691) It was discovered that the bluetooth subsystem in the Linux kernel did not properly handle HCI device initialization failure, leading to a double-free vulnerability. An attacker could use this to cause a denial of service or possibly execute arbitrary code. (CVE-2021-3564) It was discovered that the bluetooth subsystem in the Linux kernel did not properly handle HCI device detach events, leading to a use-after-free vulnerability. An attacker could use this to cause a denial of service or possibly execute arbitrary code. (CVE-2021-3573) It was discovered that the NFC implementation in the Linux kernel did not properly handle failed connect events leading to a NULL pointer dereference. A local attacker could use this to cause a denial of service. (CVE-2021-3587)

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)

USN-4997-1 fixed vulnerabilities in the Linux kernel for Ubuntu 21.04. This update provides the corresponding updates for the Linux KVM kernel for Ubuntu 21.04. Norbert Slusarek discovered a race condition in the CAN BCM networking protocol of the Linux kernel leading to multiple use-after-free vulnerabilities. A local attacker could use this issue to execute arbitrary code. (CVE-2021-3609) Piotr Krysiuk discovered that the eBPF implementation in the Linux kernel did not properly enforce limits for pointer operations. A local attacker could use this to cause a denial of service (system crash) or possibly execute arbitrary code. (CVE-2021-33200) Mathy Vanhoef discovered that the Linux kernel’s WiFi implementation did not properly clear received fragments from memory in some situations. A physically proximate attacker could possibly use this issue to inject packets or expose sensitive information. (CVE-2020-24586) Mathy Vanhoef discovered that the Linux kernel’s WiFi implementation incorrectly handled encrypted fragments. A physically proximate attacker could possibly use this issue to decrypt fragments. (CVE-2020-24587) Mathy Vanhoef discovered that the Linux kernel’s WiFi implementation incorrectly handled certain malformed frames. If a user were tricked into connecting to a malicious server, a physically proximate attacker could use this issue to inject packets. (CVE-2020-24588) Mathy Vanhoef discovered that the Linux kernel’s WiFi implementation incorrectly handled EAPOL frames from unauthenticated senders. A physically proximate attacker could inject malicious packets to cause a denial of service (system crash). (CVE-2020-26139) Mathy Vanhoef discovered that the Linux kernel’s WiFi implementation did not properly verify certain fragmented frames. A physically proximate attacker could possibly use this issue to inject or decrypt packets. (CVE-2020-26141) Mathy Vanhoef discovered that the Linux kernel’s WiFi implementation accepted plaintext fragments in certain situations. A physically proximate attacker could use this issue to inject packets. (CVE-2020-26145) Mathy Vanhoef discovered that the Linux kernel’s WiFi implementation could reassemble mixed encrypted and plaintext fragments. A physically proximate attacker could possibly use this issue to inject packets or exfiltrate selected fragments. (CVE-2020-26147) Or Cohen discovered that the SCTP implementation in the Linux kernel contained a race condition in some situations, leading to a use-after-free condition. A local attacker could use this to cause a denial of service (system crash) or possibly execute arbitrary code. (CVE-2021-23133) Or Cohen and Nadav Markus discovered a use-after-free vulnerability in the nfc implementation in the Linux kernel. A privileged local attacker could use this issue to cause a denial of service (system crash) or possibly execute arbitrary code. (CVE-2021-23134) Manfred Paul discovered that the extended Berkeley Packet Filter (eBPF) implementation in the Linux kernel contained an out-of-bounds vulnerability. A local attacker could use this issue to execute arbitrary code. (CVE-2021-31440) Piotr Krysiuk discovered that the eBPF implementation in the Linux kernel did not properly prevent speculative loads in certain situations. A local attacker could use this to expose sensitive information (kernel memory). (CVE-2021-31829) It was discovered that a race condition in the kernel Bluetooth subsystem could lead to use-after-free of slab objects. An attacker could use this issue to possibly execute arbitrary code. (CVE-2021-32399) It was discovered that a use-after-free existed in the Bluetooth HCI driver of the Linux kernel. A local attacker could use this to cause a denial of service (system crash) or possibly execute arbitrary code. (CVE-2021-33034) It was discovered that an out-of-bounds (OOB) memory access flaw existed in the f2fs module of the Linux kernel. A local attacker could use this issue to cause a denial of service (system crash). (CVE-2021-3506) Mathias Krause discovered that a null pointer dereference existed in the Nitro Enclaves kernel driver of the Linux kernel. A local attacker could use this issue to cause a denial of service or possibly execute arbitrary code. (CVE-2021-3543)

Norbert Slusarek discovered a race condition in the CAN BCM networking protocol of the Linux kernel leading to multiple use-after-free vulnerabilities. A local attacker could use this issue to execute arbitrary code. (CVE-2021-3609) Piotr Krysiuk discovered that the eBPF implementation in the Linux kernel did not properly enforce limits for pointer operations. A local attacker could use this to cause a denial of service (system crash) or possibly execute arbitrary code. (CVE-2021-33200) Mathy Vanhoef discovered that the Linux kernel’s WiFi implementation did not properly clear received fragments from memory in some situations. A physically proximate attacker could possibly use this issue to inject packets or expose sensitive information. (CVE-2020-24586) Mathy Vanhoef discovered that the Linux kernel’s WiFi implementation incorrectly handled encrypted fragments. A physically proximate attacker could possibly use this issue to decrypt fragments. (CVE-2020-24587) Mathy Vanhoef discovered that the Linux kernel’s WiFi implementation incorrectly handled certain malformed frames. If a user were tricked into connecting to a malicious server, a physically proximate attacker could use this issue to inject packets. (CVE-2020-24588) Mathy Vanhoef discovered that the Linux kernel’s WiFi implementation incorrectly handled EAPOL frames from unauthenticated senders. A physically proximate attacker could inject malicious packets to cause a denial of service (system crash). (CVE-2020-26139) Mathy Vanhoef discovered that the Linux kernel’s WiFi implementation did not properly verify certain fragmented frames. A physically proximate attacker could possibly use this issue to inject or decrypt packets. (CVE-2020-26141) Mathy Vanhoef discovered that the Linux kernel’s WiFi implementation accepted plaintext fragments in certain situations. A physically proximate attacker could use this issue to inject packets. (CVE-2020-26145) Mathy Vanhoef discovered that the Linux kernel’s WiFi implementation could reassemble mixed encrypted and plaintext fragments. A physically proximate attacker could possibly use this issue to inject packets or exfiltrate selected fragments. (CVE-2020-26147) Or Cohen discovered that the SCTP implementation in the Linux kernel contained a race condition in some situations, leading to a use-after-free condition. A local attacker could use this to cause a denial of service (system crash) or possibly execute arbitrary code. (CVE-2021-23133) Or Cohen and Nadav Markus discovered a use-after-free vulnerability in the nfc implementation in the Linux kernel. A privileged local attacker could use this issue to cause a denial of service (system crash) or possibly execute arbitrary code. (CVE-2021-23134) Manfred Paul discovered that the extended Berkeley Packet Filter (eBPF) implementation in the Linux kernel contained an out-of-bounds vulnerability. A local attacker could use this issue to execute arbitrary code. (CVE-2021-31440) Piotr Krysiuk discovered that the eBPF implementation in the Linux kernel did not properly prevent speculative loads in certain situations. A local attacker could use this to expose sensitive information (kernel memory). (CVE-2021-31829) It was discovered that a race condition in the kernel Bluetooth subsystem could lead to use-after-free of slab objects. An attacker could use this issue to possibly execute arbitrary code. (CVE-2021-32399) It was discovered that a use-after-free existed in the Bluetooth HCI driver of the Linux kernel. A local attacker could use this to cause a denial of service (system crash) or possibly execute arbitrary code. (CVE-2021-33034) It was discovered that an out-of-bounds (OOB) memory access flaw existed in the f2fs module of the Linux kernel. A local attacker could use this issue to cause a denial of service (system crash). (CVE-2021-3506) Mathias Krause discovered that a null pointer dereference existed in the Nitro Enclaves kernel driver of the Linux kernel. A local attacker could use this issue to cause a denial of service or possibly execute arbitrary code. (CVE-2021-3543)

It was discovered that BlueZ incorrectly checked certain permissions when pairing. A local attacker could possibly use this issue to impersonate devices. (CVE-2020-26558) Jay LV discovered that BlueZ incorrectly handled redundant disconnect MGMT events. A local attacker could use this issue to cause BlueZ to crash, resulting in a denial of service, or possibly execute arbitrary code. This issue only affected Ubuntu 18.04 LTS and Ubuntu 20.04 LTS. (CVE-2020-27153) Ziming Zhang discovered that BlueZ incorrectly handled certain array indexes. A local attacker could use this issue to cause BlueZ to crash, resulting in a denial of service, or possibly obtain sensitive information. This issue only affected Ubuntu 20.04 LTS and Ubuntu 20.10. (CVE-2021-3588)

Kiyin (尹亮) discovered that the NFC LLCP protocol implementation in the Linux kernel contained a reference counting error. A local attacker could use this to cause a denial of service (system crash). (CVE-2020-25670) Kiyin (尹亮) discovered that the NFC LLCP protocol implementation in the Linux kernel did not properly deallocate memory in certain error situations. A local attacker could use this to cause a denial of service (memory exhaustion). (CVE-2020-25671, CVE-2020-25672) Kiyin (尹亮) discovered that the NFC LLCP protocol implementation in the Linux kernel did not properly handle error conditions in some situations, leading to an infinite loop. A local attacker could use this to cause a denial of service. (CVE-2020-25673) Piotr Krysiuk and Benedict Schlueter discovered that the eBPF implementation in the Linux kernel performed out of bounds speculation on pointer arithmetic. A local attacker could use this to expose sensitive information. (CVE-2021-29155) Reiji Watanabe discovered that the KVM VMX implementation in the Linux kernel did not properly prevent user space from tampering with an array index value, leading to a potential out-of-bounds write. A local attacker could use this to cause a denial of service (system crash) or possibly execute arbitrary code. (CVE-2021-3501)