Canonical » Ubuntu Linux : Security Vulnerabilities, CVEs, (Code Execution)

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

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.

A local privilege escalation vulnerability was found on polkit's pkexec utility. The pkexec application is a setuid tool designed to allow unprivileged users to run commands as privileged users according predefined policies. The current version of pkexec doesn't handle the calling parameters count correctly and ends trying to execute environment variables as commands. An attacker can leverage this by crafting environment variables in such a way it'll induce pkexec to execute arbitrary code. When successfully executed the attack can cause a local privilege escalation given unprivileged users administrative rights on the target machine.

A use-after-free vulnerability was found in the virtio-net device of QEMU. It could occur when the descriptor's address belongs to the non direct access region, due to num_buffers being set after the virtqueue elem has been unmapped. A malicious guest could use this flaw to crash QEMU, resulting in a denial of service condition, or potentially execute code on the host with the privileges of the QEMU process.

It was discovered that the eBPF implementation in the Linux kernel did not properly track bounds information for 32 bit registers when performing div and mod operations. A local attacker could use this to possibly execute arbitrary code.

Ubuntu's packaging of libvirt in 20.04 LTS created a control socket with world read and write permissions. An attacker could use this to overwrite arbitrary files or execute arbitrary code.

Integer overflows were discovered in the functions grub_cmd_initrd and grub_initrd_init in the efilinux component of GRUB2, as shipped in Debian, Red Hat, and Ubuntu (the functionality is not included in GRUB2 upstream), leading to a heap-based buffer overflow. These could be triggered by an extremely large number of arguments to the initrd command on 32-bit architectures, or a crafted filesystem with very large files on any architecture. An attacker could use this to execute arbitrary code and bypass UEFI Secure Boot restrictions. This issue affects GRUB2 version 2.04 and prior versions.

TOCTOU Race Condition vulnerability in apport allows a local attacker to escalate privileges and execute arbitrary code. An attacker may exit the crashed process and exploit PID recycling to spawn a root process with the same PID as the crashed process, which can then be used to escalate privileges. Fixed in 2.20.1-0ubuntu2.24, 2.20.9 versions prior to 2.20.9-0ubuntu7.16 and 2.20.11 versions prior to 2.20.11-0ubuntu27.6. Was ZDI-CAN-11234.

A heap buffer overflow in SANE Backends before 1.0.30 may allow a malicious device connected to the same local network as the victim to execute arbitrary code, aka GHSL-2020-084.

A heap buffer overflow in SANE Backends before 1.0.30 allows a malicious device connected to the same local network as the victim to execute arbitrary code, aka GHSL-2020-080.

An issue was discovered in Squid before 5.0.2. A remote attacker can replay a sniffed Digest Authentication nonce to gain access to resources that are otherwise forbidden. This occurs because the attacker can overflow the nonce reference counter (a short integer). Remote code execution may occur if the pooled token credentials are freed (instead of replayed as valid credentials).

A use-after-free issue exists in WebKitGTK before 2.28.1 and WPE WebKit before 2.28.1 via crafted web content that allows remote attackers to execute arbitrary code or cause a denial of service (memory corruption and application crash).

In hpack_dht_insert in hpack-tbl.c in the HPACK decoder in HAProxy 1.8 through 2.x before 2.1.4, a remote attacker can write arbitrary bytes around a certain location on the heap via a crafted HTTP/2 request, possibly causing remote code execution.

When using Apache Tomcat versions 10.0.0-M1 to 10.0.0-M4, 9.0.0.M1 to 9.0.34, 8.5.0 to 8.5.54 and 7.0.0 to 7.0.103 if a) an attacker is able to control the contents and name of a file on the server; and b) the server is configured to use the PersistenceManager with a FileStore; and c) the PersistenceManager is configured with sessionAttributeValueClassNameFilter="null" (the default unless a SecurityManager is used) or a sufficiently lax filter to allow the attacker provided object to be deserialized; and d) the attacker knows the relative file path from the storage location used by FileStore to the file the attacker has control over; then, using a specifically crafted request, the attacker will be able to trigger remote code execution via deserialization of the file under their control. Note that all of conditions a) to d) must be true for the attack to succeed.

OpenSMTPD before 6.6.4 allows remote code execution because of an out-of-bounds read in mta_io in mta_session.c for multi-line replies. Although this vulnerability affects the client side of OpenSMTPD, it is possible to attack a server because the server code launches the client code during bounce handling.

sa-exim 4.2.1 allows attackers to execute arbitrary code if they can write a .cf file or a rule. This occurs because Greylisting.pm relies on eval (rather than direct parsing and/or use of the taint feature). This issue is similar to CVE-2018-11805.

An issue was discovered in Squid 2.x, 3.x, and 4.x through 4.8. Due to incorrect data management, it is vulnerable to information disclosure when processing HTTP Digest Authentication. Nonce tokens contain the raw byte value of a pointer that sits within heap memory allocation. This information reduces ASLR protections and may aid attackers isolating memory areas to target for remote code execution attacks.

Included in Log4j 1.2 is a SocketServer class that is vulnerable to deserialization of untrusted data which can be exploited to remotely execute arbitrary code when combined with a deserialization gadget when listening to untrusted network traffic for log data. This affects Log4j versions up to 1.2 up to 1.2.17.

An untrusted deserialization was found in the org.apache.xmlrpc.parser.XmlRpcResponseParser:addResult method of Apache XML-RPC (aka ws-xmlrpc) library. A malicious XML-RPC server could target a XML-RPC client causing it to execute arbitrary code. Apache XML-RPC is no longer maintained and this issue will not be fixed.

In SaltStack Salt through 2019.2.0, the salt-api NET API with the ssh client enabled is vulnerable to command injection. This allows an unauthenticated attacker with network access to the API endpoint to execute arbitrary code on the salt-api host.

Exim 4.92 through 4.92.2 allows remote code execution, a different vulnerability than CVE-2019-15846. There is a heap-based buffer overflow in string_vformat in string.c involving a long EHLO command.

In shiftfs, a non-upstream patch to the Linux kernel included in the Ubuntu 5.0 and 5.3 kernel series, shiftfs_btrfs_ioctl_fd_replace() calls fdget(oldfd), then without further checks passes the resulting file* into shiftfs_real_fdget(), which casts file->private_data, a void* that points to a filesystem-dependent type, to a "struct shiftfs_file_info *". As the private_data is not required to be a pointer, an attacker can use this to cause a denial of service or possibly execute arbitrary code.

A heap overflow flaw was found in the Linux kernel, all versions 3.x.x and 4.x.x before 4.18.0, in Marvell WiFi chip driver. The vulnerability allows a remote attacker to cause a system crash, resulting in a denial of service, or execute arbitrary code. The highest threat with this vulnerability is with the availability of the system. If code execution occurs, the code will run with the permissions of root. This will affect both confidentiality and integrity of files on the system.

A stack-based buffer overflow was found in the Linux kernel, version kernel-2.6.32, in Marvell WiFi chip driver. An attacker is able to cause a denial of service (system crash) or, possibly execute arbitrary code, when a STA works in IBSS mode (allows connecting stations together without the use of an AP) and connects to another STA.

A heap-based buffer overflow vulnerability was found in the Linux kernel, version kernel-2.6.32, in Marvell WiFi chip driver. A remote attacker could cause a denial of service (system crash) or, possibly execute arbitrary code, when the lbs_ibss_join_existing function is called after a STA connects to an AP.