Ubuntu Secutity Notices

It was discovered that wpa_supplicant did not properly handle P2P (Wi-Fi Direct) provision discovery requests in some situations. A physically proximate attacker could use this to cause a denial of service or possibly execute arbitrary code.

USN-4754-1 fixed vulnerabilities in Python. Because of a regression, a subsequent update removed the fix for CVE-2021-3177. This update reinstates the security fix for CVE-2021-3177. We apologize for the inconvenience. Original advisory details: It was discovered that Python incorrectly handled certain inputs. An attacker could possibly use this issue to execute arbitrary code or cause a denial of service. (CVE-2020-27619, CVE-2021-3177)

USN-4737-1 fixed a vulnerability in Bind. This update provides the corresponding update for Ubuntu 12.04 ESM and Ubuntu 14.04 ESM. Original advisory details: It was discovered that Bind incorrectly handled GSSAPI security policy negotiation. A remote attacker could use this issue to cause Bind to crash, resulting in a denial of service, or possibly execute arbitrary code. In the default installation, attackers would be isolated by the Bind AppArmor profile.

Multiple security issues were discovered in Firefox. If a user were tricked into opening a specially crafted website, an attacker could potentially exploit these to cause a denial of service, obtain sensitive information, conduct cross-site scripting (XSS) attacks, bypass HTTP auth phishing warnings, or execute arbitrary code.

USN-4754-1 fixed a vulnerability in Python. The fix for CVE-2021-3177 introduced a regression in Python 2.7. This update reverts the security fix pending further investigation. We apologize for the inconvenience. Original advisory details: It was discovered that Python incorrectly handled certain inputs. An attacker could possibly use this issue to execute arbitrary code or cause a denial of service. (CVE-2020-27619, CVE-2021-3177)

It was discovered that LibTIFF incorrectly handled certain malformed images. If a user or automated system were tricked into opening a specially crafted image, a remote attacker could crash the application, leading to a denial of service, or possibly execute arbitrary code with user privileges.

It was discovered that Python incorrectly handled certain inputs. An attacker could possibly use this issue to execute arbitrary code or cause a denial of service. (CVE-2020-27619, CVE-2021-3177)

Bodong Zhao discovered a use-after-free in the Sun keyboard driver implementation in the Linux kernel. A local attacker could use this to cause a denial of service or possibly execute arbitrary code. (CVE-2020-25669) It was discovered that the jfs file system implementation in the Linux kernel contained an out-of-bounds read vulnerability. A local attacker could use this to possibly cause a denial of service (system crash). (CVE-2020-27815) Shisong Qin and Bodong Zhao discovered that Speakup screen reader driver in the Linux kernel did not correctly handle setting line discipline in some situations. A local attacker could use this to cause a denial of service (system crash). (CVE-2020-27830, CVE-2020-28941) It was discovered that the memory management subsystem in the Linux kernel did not properly handle copy-on-write operations in some situations. A local attacker could possibly use this to gain unintended write access to read-only memory pages. (CVE-2020-29374) Michael Kurth and Pawel Wieczorkiewicz discovered that the Xen event processing backend in the Linux kernel did not properly limit the number of events queued. An attacker in a guest VM could use this to cause a denial of service in the host OS. (CVE-2020-29568) Olivier Benjamin and Pawel Wieczorkiewicz discovered a race condition the Xen paravirt block backend in the Linux kernel, leading to a use-after-free vulnerability. An attacker in a guest VM could use this to cause a denial of service in the host OS. (CVE-2020-29569) Jann Horn discovered that the tty subsystem of the Linux kernel did not use consistent locking in some situations, leading to a read-after-free vulnerability. A local attacker could use this to cause a denial of service (system crash) or possibly expose sensitive information (kernel memory). (CVE-2020-29660) Jann Horn discovered a race condition in the tty subsystem of the Linux kernel in the locking for the TIOCSPGRP ioctl(), leading to a use-after- free vulnerability. A local attacker could use this to cause a denial of service (system crash) or possibly execute arbitrary code. (CVE-2020-29661)

It was discovered that the LIO SCSI target implementation in the Linux kernel performed insufficient identifier checking in certain XCOPY requests. An attacker with access to at least one LUN in a multiple backstore environment could use this to expose sensitive information or modify data.

Daniele Antonioli, Nils Ole Tippenhauer, and Kasper Rasmussen discovered that legacy pairing and secure-connections pairing authentication in the Bluetooth protocol could allow an unauthenticated user to complete authentication without pairing credentials via adjacent access. A physically proximate attacker could use this to impersonate a previously paired Bluetooth device. (CVE-2020-10135) Jay Shin discovered that the ext4 file system implementation in the Linux kernel did not properly handle directory access with broken indexing, leading to an out-of-bounds read vulnerability. A local attacker could use this to cause a denial of service (system crash). (CVE-2020-14314) It was discovered that the block layer implementation in the Linux kernel did not properly perform reference counting in some situations, leading to a use-after-free vulnerability. A local attacker could use this to cause a denial of service (system crash). (CVE-2020-15436) It was discovered that the serial port driver in the Linux kernel did not properly initialize a pointer in some situations. A local attacker could possibly use this to cause a denial of service (system crash). (CVE-2020-15437) Andy Nguyen discovered that the Bluetooth HCI event packet parser in the Linux kernel did not properly handle event advertisements of certain sizes, leading to a heap-based buffer overflow. A physically proximate remote attacker could use this to cause a denial of service (system crash) or possibly execute arbitrary code. (CVE-2020-24490) It was discovered that the NFS client implementation in the Linux kernel did not properly perform bounds checking before copying security labels in some situations. A local attacker could use this to cause a denial of service (system crash) or possibly execute arbitrary code. (CVE-2020-25212) It was discovered that the Rados block device (rbd) driver in the Linux kernel did not properly perform privilege checks for access to rbd devices in some situations. A local attacker could use this to map or unmap rbd block devices. (CVE-2020-25284) It was discovered that the block layer subsystem in the Linux kernel did not properly handle zero-length requests. A local attacker could use this to cause a denial of service. (CVE-2020-25641) It was discovered that the HDLC PPP implementation in the Linux kernel did not properly validate input in some situations. A local attacker could use this to cause a denial of service (system crash) or possibly execute arbitrary code. (CVE-2020-25643) Kiyin (尹亮) discovered that the perf subsystem in the Linux kernel did not properly deallocate memory in some situations. A privileged attacker could use this to cause a denial of service (kernel memory exhaustion). (CVE-2020-25704) It was discovered that the KVM hypervisor in the Linux kernel did not properly handle interrupts in certain situations. A local attacker in a guest VM could possibly use this to cause a denial of service (host system crash). (CVE-2020-27152) It was discovered that the jfs file system implementation in the Linux kernel contained an out-of-bounds read vulnerability. A local attacker could use this to possibly cause a denial of service (system crash). (CVE-2020-27815) It was discovered that an information leak existed in the syscall implementation in the Linux kernel on 32 bit systems. A local attacker could use this to expose sensitive information (kernel memory). (CVE-2020-28588) It was discovered that the framebuffer implementation in the Linux kernel did not properly perform range checks in certain situations. A local attacker could use this to expose sensitive information (kernel memory). (CVE-2020-28915) Jann Horn discovered a race condition in the copy-on-write implementation in the Linux kernel when handling hugepages. A local attacker could use this to gain unintended write access to read-only memory pages. (CVE-2020-29368) Jann Horn discovered that the mmap implementation in the Linux kernel contained a race condition when handling munmap() operations, leading to a read-after-free vulnerability. A local attacker could use this to cause a denial of service (system crash) or possibly expose sensitive information. (CVE-2020-29369) Jann Horn discovered that the romfs file system in the Linux kernel did not properly validate file system meta-data, leading to an out-of-bounds read. An attacker could use this to construct a malicious romfs image that, when mounted, exposed sensitive information (kernel memory). (CVE-2020-29371) Jann Horn discovered that the tty subsystem of the Linux kernel did not use consistent locking in some situations, leading to a read-after-free vulnerability. A local attacker could use this to cause a denial of service (system crash) or possibly expose sensitive information (kernel memory). (CVE-2020-29660) Jann Horn discovered a race condition in the tty subsystem of the Linux kernel in the locking for the TIOCSPGRP ioctl(), leading to a use-after- free vulnerability. A local attacker could use this to cause a denial of service (system crash) or possibly execute arbitrary code. (CVE-2020-29661) It was discovered that a race condition existed that caused the Linux kernel to not properly restrict exit signal delivery. A local attacker could possibly use this to send signals to arbitrary processes. (CVE-2020-35508)

It was discovered that the console keyboard driver in the Linux kernel contained a race condition. A local attacker could use this to expose sensitive information (kernel memory). (CVE-2020-25656) Minh Yuan discovered that the tty driver in the Linux kernel contained race conditions when handling fonts. A local attacker could possibly use this to expose sensitive information (kernel memory). (CVE-2020-25668) Bodong Zhao discovered a use-after-free in the Sun keyboard driver implementation in the Linux kernel. A local attacker could use this to cause a denial of service or possibly execute arbitrary code. (CVE-2020-25669) Kiyin (尹亮) discovered that the perf subsystem in the Linux kernel did not properly deallocate memory in some situations. A privileged attacker could use this to cause a denial of service (kernel memory exhaustion). (CVE-2020-25704) Julien Grall discovered that the Xen dom0 event handler in the Linux kernel did not properly limit the number of events queued. An attacker in a guest VM could use this to cause a denial of service in the host OS. (CVE-2020-27673) Jinoh Kang discovered that the Xen event channel infrastructure in the Linux kernel contained a race condition. An attacker in guest could possibly use this to cause a denial of service (dom0 crash). (CVE-2020-27675) Daniel Axtens discovered that PowerPC RTAS implementation in the Linux kernel did not properly restrict memory accesses in some situations. A privileged local attacker could use this to arbitrarily modify kernel memory, potentially bypassing kernel lockdown restrictions. (CVE-2020-27777) It was discovered that the jfs file system implementation in the Linux kernel contained an out-of-bounds read vulnerability. A local attacker could use this to possibly cause a denial of service (system crash). (CVE-2020-27815) Shisong Qin and Bodong Zhao discovered that Speakup screen reader driver in the Linux kernel did not correctly handle setting line discipline in some situations. A local attacker could use this to cause a denial of service (system crash). (CVE-2020-27830, CVE-2020-28941) It was discovered that a use-after-free vulnerability existed in the infiniband hfi1 device driver in the Linux kernel. A local attacker could possibly use this to cause a denial of service (system crash). (CVE-2020-27835) It was discovered that an information leak existed in the syscall implementation in the Linux kernel on 32 bit systems. A local attacker could use this to expose sensitive information (kernel memory). (CVE-2020-28588) Minh Yuan discovered that the framebuffer console driver in the Linux kernel did not properly handle fonts in some conditions. A local attacker could use this to cause a denial of service (system crash) or possibly expose sensitive information (kernel memory). (CVE-2020-28974) Michael Kurth and Pawel Wieczorkiewicz discovered that the Xen event processing backend in the Linux kernel did not properly limit the number of events queued. An attacker in a guest VM could use this to cause a denial of service in the host OS. (CVE-2020-29568) Olivier Benjamin and Pawel Wieczorkiewicz discovered a race condition the Xen paravirt block backend in the Linux kernel, leading to a use-after-free vulnerability. An attacker in a guest VM could use this to cause a denial of service in the host OS. (CVE-2020-29569) Jann Horn discovered that the tty subsystem of the Linux kernel did not use consistent locking in some situations, leading to a read-after-free vulnerability. A local attacker could use this to cause a denial of service (system crash) or possibly expose sensitive information (kernel memory). (CVE-2020-29660) Jann Horn discovered a race condition in the tty subsystem of the Linux kernel in the locking for the TIOCSPGRP ioctl(), leading to a use-after- free vulnerability. A local attacker could use this to cause a denial of service (system crash) or possibly execute arbitrary code. (CVE-2020-29661) It was discovered that a race condition existed that caused the Linux kernel to not properly restrict exit signal delivery. A local attacker could possibly use this to send signals to arbitrary processes. (CVE-2020-35508)

Bodong Zhao discovered a use-after-free in the Sun keyboard driver implementation in the Linux kernel. A local attacker could use this to cause a denial of service or possibly execute arbitrary code. (CVE-2020-25669) It was discovered that the jfs file system implementation in the Linux kernel contained an out-of-bounds read vulnerability. A local attacker could use this to possibly cause a denial of service (system crash). (CVE-2020-27815) Shisong Qin and Bodong Zhao discovered that Speakup screen reader driver in the Linux kernel did not correctly handle setting line discipline in some situations. A local attacker could use this to cause a denial of service (system crash). (CVE-2020-27830, CVE-2020-28941) It was discovered that an information leak existed in the syscall implementation in the Linux kernel on 32 bit systems. A local attacker could use this to expose sensitive information (kernel memory). (CVE-2020-28588) Michael Kurth and Pawel Wieczorkiewicz discovered that the Xen event processing backend in the Linux kernel did not properly limit the number of events queued. An attacker in a guest VM could use this to cause a denial of service in the host OS. (CVE-2020-29568) Olivier Benjamin and Pawel Wieczorkiewicz discovered a race condition the Xen paravirt block backend in the Linux kernel, leading to a use-after-free vulnerability. An attacker in a guest VM could use this to cause a denial of service in the host OS. (CVE-2020-29569) Jann Horn discovered that the tty subsystem of the Linux kernel did not use consistent locking in some situations, leading to a read-after-free vulnerability. A local attacker could use this to cause a denial of service (system crash) or possibly expose sensitive information (kernel memory). (CVE-2020-29660) Jann Horn discovered a race condition in the tty subsystem of the Linux kernel in the locking for the TIOCSPGRP ioctl(), leading to a use-after- free vulnerability. A local attacker could use this to cause a denial of service (system crash) or possibly execute arbitrary code. (CVE-2020-29661) It was discovered that the netfilter subsystem in the Linux kernel did not properly handle filter rules in some situations. A local attacker with the CAP_NET_ADMIN capability could use this to cause a denial of service. (CVE-2021-20177)

It was discovered that the jfs file system implementation in the Linux kernel contained an out-of-bounds read vulnerability. A local attacker could use this to possibly cause a denial of service (system crash). (CVE-2020-27815) It was discovered that the memory management subsystem in the Linux kernel did not properly handle copy-on-write operations in some situations. A local attacker could possibly use this to gain unintended write access to read-only memory pages. (CVE-2020-29374) Michael Kurth and Pawel Wieczorkiewicz discovered that the Xen event processing backend in the Linux kernel did not properly limit the number of events queued. An attacker in a guest VM could use this to cause a denial of service in the host OS. (CVE-2020-29568) Jann Horn discovered that the tty subsystem of the Linux kernel did not use consistent locking in some situations, leading to a read-after-free vulnerability. A local attacker could use this to cause a denial of service (system crash) or possibly expose sensitive information (kernel memory). (CVE-2020-29660) Jann Horn discovered a race condition in the tty subsystem of the Linux kernel in the locking for the TIOCSPGRP ioctl(), leading to a use-after- free vulnerability. A local attacker could use this to cause a denial of service (system crash) or possibly execute arbitrary code. (CVE-2020-29661)

USN-4747-1 fixed a vulnerability in screen. This update provides the corresponding update for Ubuntu 14.04 ESM. Original advisory details: Felix Weinmann discovered that GNU Screen incorrectly handled certain character sequences. A remote attacker could use this issue to cause GNU Screen to crash, resulting in a denial of service, or possibly execute arbitrary code.

Felix Weinmann discovered that GNU Screen incorrectly handled certain character sequences. A remote attacker could use this issue to cause GNU Screen to crash, resulting in a denial of service, or possibly execute arbitrary code.

Tavis Ormandy discovered that xterm incorrectly handled certain character sequences. A remote attacker could use this issue to cause xterm to crash, resulting in a denial of service, or possibly execute arbitrary code.

USN-4698-1 fixed vulnerabilities in Dnsmasq. The updates introduced regressions in certain environments related to issues with multiple queries, and issues with retries. This update fixes the problem. Original advisory details: Moshe Kol and Shlomi Oberman discovered that Dnsmasq incorrectly handled memory when sorting RRsets. A remote attacker could use this issue to cause Dnsmasq to hang, resulting in a denial of service, or possibly execute arbitrary code. (CVE-2020-25681, CVE-2020-25687) Moshe Kol and Shlomi Oberman discovered that Dnsmasq incorrectly handled extracting certain names. A remote attacker could use this issue to cause Dnsmasq to hang, resulting in a denial of service, or possibly execute arbitrary code. (CVE-2020-25682, CVE-2020-25683) Moshe Kol and Shlomi Oberman discovered that Dnsmasq incorrectly implemented address/port checks. A remote attacker could use this issue to perform a cache poisoning attack. (CVE-2020-25684) Moshe Kol and Shlomi Oberman discovered that Dnsmasq incorrectly implemented query resource name checks. A remote attacker could use this issue to perform a cache poisoning attack. (CVE-2020-25685) Moshe Kol and Shlomi Oberman discovered that Dnsmasq incorrectly handled multiple query requests for the same resource name. A remote attacker could use this issue to perform a cache poisoning attack. (CVE-2020-25686) It was discovered that Dnsmasq incorrectly handled memory during DHCP response creation. A remote attacker could possibly use this issue to cause Dnsmasq to consume resources, leading to a denial of service. This issue only affected Ubuntu 16.04 LTS, Ubuntu 18.04 LTS, and Ubuntu 20.04 LTS. (CVE-2019-14834)

David Benjamin discovered that OpenSSL incorrectly handled comparing certificates containing a EDIPartyName name type. A remote attacker could possibly use this issue to cause OpenSSL to crash, resulting in a denial of service. (CVE-2020-1971) Tavis Ormandy discovered that OpenSSL incorrectly handled parsing issuer fields. A remote attacker could possibly use this issue to cause OpenSSL to crash, resulting in a denial of service. (CVE-2021-23841)

USN-4467-1 fixed vulnerabilities in QEMU. The fix for CVE-2020-13754 introduced a regression in certain environments. This update fixes the problem. We apologize for the inconvenience. Original advisory details: Ren Ding, Hanqing Zhao, Alexander Bulekov, and Anatoly Trosinenko discovered that the QEMU incorrectly handled certain msi-x mmio operations. An attacker inside a guest could possibly use this issue to cause QEMU to crash, resulting in a denial of service. (CVE-2020-13754)

Pasi Saarinen discovered that OpenLDAP incorrectly handled certain short timestamps. A remote attacker could possibly use this issue to cause OpenLDAP to crash, resulting in a denial of service.