Canonical » Ubuntu Linux » 20.04 lts : Security Vulnerabilities

In Ubuntu's accountsservice an unprivileged local attacker can trigger a use-after-free vulnerability in accountsservice by sending a D-Bus message to the accounts-daemon process.

Jean-Baptiste Cayrou discovered that the shiftfs file system in the Ubuntu Linux kernel contained a race condition when handling inode locking in some situations. A local attacker could use this to cause a denial of service (kernel deadlock).

Sensitive data could be exposed in logs of cloud-init before version 23.1.2. An attacker could use this information to find hashed passwords and possibly escalate their privilege.

Using the TIOCLINUX ioctl request, a malicious snap could inject contents into the input of the controlling terminal which could allow it to cause arbitrary commands to be executed outside of the snap sandbox after the snap exits. Graphical terminal emulators like xterm, gnome-terminal and others are not affected - this can only be exploited when snaps are run on a virtual console.

A privilege escalation attack was found in apport-cli 2.26.0 and earlier which is similar to CVE-2023-26604. If a system is specially configured to allow unprivileged users to run sudo apport-cli, less is configured as the pager, and the terminal size can be set: a local attacker can escalate privilege. It is extremely unlikely that a system administrator would configure sudo to allow unprivileged users to perform this class of exploit.

A buffer overflow vulnerability was found in the Netfilter subsystem in the Linux Kernel. This issue could allow the leakage of both stack and heap addresses, and potentially allow Local Privilege Escalation to the root user via arbitrary code execution.

mm/mremap.c in the Linux kernel before 5.13.3 has a use-after-free via a stale TLB because an rmap lock is not held during a PUD move.

strongSwan before 5.9.8 allows remote attackers to cause a denial of service in the revocation plugin by sending a crafted end-entity (and intermediate CA) certificate that contains a CRL/OCSP URL that points to a server (under the attacker's control) that doesn't properly respond but (for example) just does nothing after the initial TCP handshake, or sends an excessive amount of application data.

BlueZ before 5.59 allows physically proximate attackers to cause a denial of service because malformed and invalid capabilities can be processed in profiles/audio/avdtp.c.

BlueZ before 5.59 allows physically proximate attackers to obtain sensitive information because profiles/audio/avrcp.c does not validate params_len.

An issue was discovered in the Linux kernel through 5.18.9. A type confusion bug in nft_set_elem_init (leading to a buffer overflow) could be used by a local attacker to escalate privileges, a different vulnerability than CVE-2022-32250. (The attacker can obtain root access, but must start with an unprivileged user namespace to obtain CAP_NET_ADMIN access.) This can be fixed in nft_setelem_parse_data in net/netfilter/nf_tables_api.c.

Improper Update of Reference Count vulnerability in net/sched of Linux Kernel allows local attacker to cause privilege escalation to root. This issue affects: Linux Kernel versions prior to 5.18; version 4.14 and later versions.

A vulnerability in the OOXML parsing module in Clam AntiVirus (ClamAV) Software version 0.104.1 and LTS version 0.103.4 and prior versions could allow an unauthenticated, remote attacker to cause a denial of service condition on an affected device. The vulnerability is due to improper checks that may result in an invalid pointer read. An attacker could exploit this vulnerability by sending a crafted OOXML file to an affected device. An exploit could allow the attacker to cause the ClamAV scanning process to crash, resulting in a denial of service condition.

Sensitive data could be exposed in world readable logs of cloud-init before version 22.3 when schema failures are reported. This leak could include hashed passwords.

A use-after-free exists in the Linux Kernel in tc_new_tfilter that could allow a local attacker to gain privilege escalation. The exploit requires unprivileged user namespaces. We recommend upgrading past commit 04c2a47ffb13c29778e2a14e414ad4cb5a5db4b5

A vulnerability was found in the Linux kernel’s cgroup_release_agent_write in the kernel/cgroup/cgroup-v1.c function. This flaw, under certain circumstances, allows the use of the cgroups v1 release_agent feature to escalate privileges and bypass the namespace isolation unexpectedly.

AIDE before 0.17.4 allows local users to obtain root privileges via crafted file metadata (such as XFS extended attributes or tmpfs ACLs), because of a heap-based buffer overflow.

In strongSwan before 5.9.5, a malicious responder can send an EAP-Success message too early without actually authenticating the client and (in the case of EAP methods with mutual authentication and EAP-only authentication for IKEv2) even without server authentication.

A race condition existed in the snapd 2.54.2 snap-confine binary when preparing a private mount namespace for a snap. This could allow a local attacker to gain root privileges by bind-mounting their own contents inside the snap's private mount namespace and causing snap-confine to execute arbitrary code and hence gain privilege escalation. Fixed in snapd versions 2.54.3+18.04, 2.54.3+20.04 and 2.54.3+21.10.1

snapd 2.54.2 did not properly validate the location of the snap-confine binary. A local attacker who can hardlink this binary to another location to cause snap-confine to execute other arbitrary binaries and hence gain privilege escalation. Fixed in snapd versions 2.54.3+18.04, 2.54.3+20.04 and 2.54.3+21.10.1

In Django 2.2 before 2.2.25, 3.1 before 3.1.14, and 3.2 before 3.2.10, HTTP requests for URLs with trailing newlines could bypass upstream access control based on URL paths.

The Samba vfs_fruit module uses extended file attributes (EA, xattr) to provide "...enhanced compatibility with Apple SMB clients and interoperability with a Netatalk 3 AFP fileserver." Samba versions prior to 4.13.17, 4.14.12 and 4.15.5 with vfs_fruit configured allow out-of-bounds heap read and write via specially crafted extended file attributes. A remote attacker with write access to extended file attributes can execute arbitrary code with the privileges of smbd, typically root.

It was discovered that read_file() in apport/hookutils.py would follow symbolic links or open FIFOs. When this function is used by the xorg-hwe-18.04 package apport hooks, it could expose private data to other local users.

It was discovered that read_file() in apport/hookutils.py would follow symbolic links or open FIFOs. When this function is used by the xorg package apport hooks, it could expose private data to other local users.

It was discovered that read_file() in apport/hookutils.py would follow symbolic links or open FIFOs. When this function is used by the openjdk-17 package apport hooks, it could expose private data to other local users.