SECURITY

USN-4985-1: Intel Microcode vulnerabilities It was discovered that some Intel processors may not properly invalidate cache entries used by Intel Virtualization Technology for Directed I/O (VT-d). This may allow a local user to perform a privilege escalation attack. (CVE-2021-24489) Joseph Nuzman discovered that some Intel processors may not properly apply EIBRS mitigations (originally developed for CVE-2017-5715) and hence may allow unauthorized memory reads via sidechannel attacks. A local attacker could use this to expose sensitive information, including kernel memory. (CVE-2020-24511) Travis Downs discovered that some Intel processors did not properly flush cache-lines for trivial-data values. This may allow an unauthorized user to infer the presence of these trivial-data-cache-lines via timing sidechannel attacks. A local attacker could use this to expose sensitive information. (CVE-2020-24512) It was discovered that certain Intel Atom processors could expose memory contents stored in microarchitectural buffers. A [ more… ]

USN-4937-2: GNOME Autoar regression USN-4937-1 fixed a vulnerability in GNOME Autoar. The update caused a regression when extracting certain archives. This update fixes the problem. Original advisory details: Ondrej Holy discovered that GNOME Autoar could extract files outside of the intended directory. If a user were tricked into extracting a specially crafted archive, a remote attacker could create files in arbitrary locations, possibly leading to code execution. Source: USN-4937-2: GNOME Autoar regression

USN-4969-3: DHCP regression USN-4969-1 fixed a vulnerability in DHCP. The package for Ubuntu 21.04 introduced a regression causing it to reject certain valid configuration files. This update fixes the problem. We apologize for the inconvenience. Original advisory details: Jon Franklin and Pawel Wieczorkiewicz discovered that DHCP incorrectly handled lease file parsing. A remote attacker could possibly use this issue to cause DHCP to crash, resulting in a denial of service. Source: USN-4969-3: DHCP regression

USN-4975-2: Django vulnerability USN-4975-1 fixed a vulnerability in Django. This update provides the corresponding update for Ubuntu 16.04 ESM. Original advisory details: Rasmus Lerchedahl Petersen and Rasmus Wriedt Larsen discovered that Django incorrectly handled path sanitation in admindocs. A remote attacker could possibly use this issue to determine the existence of arbitrary files and in certain configurations obtain their contents. (CVE-2021-33203) Source: USN-4975-2: Django vulnerability

USN-4984-1: Linux kernel vulnerabilities Jan Beulich discovered that the Xen netback backend in the Linux kernel did not properly handle certain error conditions under paravirtualization. An attacker in a guest VM could possibly use this to cause a denial of service (host domain crash). (CVE-2021-28038) It was discovered that the Realtek RTL8188EU Wireless device driver in the Linux kernel did not properly validate ssid lengths in some situations. An attacker could use this to cause a denial of service (system crash). (CVE-2021-28660) It was discovered that the Xen paravirtualization backend in the Linux kernel did not properly deallocate memory in some situations. A local attacker could use this to cause a denial of service (memory exhaustion). (CVE-2021-28688) It was discovered that the fuse user space file system implementation in the Linux kernel did not properly handle bad inodes in some [ more… ]