Canonical Ubuntu Linux

In the Linux kernel 4.15.x through 4.19.x before 4.19.2, map_write() in kernel/user_namespace.c allows privilege escalation because it mishandles nested user namespaces with more than 5 UID or GID ranges. A user who has CAP_SYS_ADMIN in an affected user namespace can bypass access controls on resources outside the namespace, as demonstrated by reading /etc/shadow. This occurs because an ID transformation takes place properly for the namespaced-to-kernel direction but not for the kernel-to-namespaced direction.

Multiple race conditions in fs/pipe.c in the Linux kernel before 2.6.32-rc6 allow local users to cause a denial of service (NULL pointer dereference and system crash) or gain privileges by attempting to open an anonymous pipe via a /proc/*/fd/ pathname.

io_uring UAF, Unix SCM garbage collection

When Apache Tomcat 9.0.0.M1 to 9.0.28, 8.5.0 to 8.5.47, 7.0.0 and 7.0.97 is configured with the JMX Remote Lifecycle Listener, a local attacker without access to the Tomcat process or configuration files is able to manipulate the RMI registry to perform a man-in-the-middle attack to capture user names and passwords used to access the JMX interface. The attacker can then use these credentials to access the JMX interface and gain complete control over the Tomcat instance.

ext/fts3/fts3.c in SQLite before 3.32.0 has a use-after-free in fts3EvalNextRow, related to the snippet feature.

An issue was discovered in drivers/media/platform/vivid in the Linux kernel through 5.3.8. It is exploitable for privilege escalation on some Linux distributions where local users have /dev/video0 access, but only if the driver happens to be loaded. There are multiple race conditions during streaming stopping in this driver (part of the V4L2 subsystem). These issues are caused by wrong mutex locking in vivid_stop_generating_vid_cap(), vivid_stop_generating_vid_out(), sdr_cap_stop_streaming(), and the corresponding kthreads. At least one of these race conditions leads to a use-after-free.

Race condition in Apport before 2.17.2-0ubuntu1.1 as packaged in Ubuntu 15.04, before 2.14.70ubuntu8.5 as packaged in Ubuntu 14.10, before 2.14.1-0ubuntu3.11 as packaged in Ubuntu 14.04 LTS, and before 2.0.1-0ubuntu17.9 as packaged in Ubuntu 12.04 LTS allow local users to write to arbitrary files and gain root privileges.

The BPF subsystem in the Linux kernel before 4.5.5 mishandles reference counts, which allows local users to cause a denial of service (use-after-free) or possibly have unspecified other impact via a crafted application on (1) a system with more than 32 Gb of memory, related to the program reference count or (2) a 1 Tb system, related to the map reference count.

A flaw was found in the Linux kernel's handle_rx() function in the [vhost_net] driver. A malicious virtual guest, under specific conditions, can trigger an out-of-bounds write in a kmalloc-8 slab on a virtual host which may lead to a kernel memory corruption and a system panic. Due to the nature of the flaw, privilege escalation cannot be fully ruled out. Versions from v4.16 and newer are vulnerable.

An out-of-bounds write vulnerability was found in glibc before 2.31 when handling signal trampolines on PowerPC. Specifically, the backtrace function did not properly check the array bounds when storing the frame address, resulting in a denial of service or potential code execution. The highest threat from this vulnerability is to system availability.

A use-after-free vulnerability introduced in glibc upstream version 2.14 was found in the way the tilde expansion was carried out. Directory paths containing an initial tilde followed by a valid username were affected by this issue. A local attacker could exploit this flaw by creating a specially crafted path that, when processed by the glob function, would potentially lead to arbitrary code execution. This was fixed in version 2.32.

TOCTOU in apport

In postgresql 9.3.x before 9.3.21, 9.4.x before 9.4.16, 9.5.x before 9.5.11, 9.6.x before 9.6.7 and 10.x before 10.2, pg_upgrade creates file in current working directory containing the output of `pg_dumpall -g` under umask which was in effect when the user invoked pg_upgrade, and not under 0077 which is normally used for other temporary files. This can allow an authenticated attacker to read or modify the one file, which may contain encrypted or unencrypted database passwords. The attack is infeasible if a directory mode blocks the attacker searching the current working directory or if the prevailing umask blocks the attacker opening the file.

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.

runc through 1.0.0-rc9 has Incorrect Access Control leading to Escalation of Privileges, related to libcontainer/rootfs_linux.go. To exploit this, an attacker must be able to spawn two containers with custom volume-mount configurations, and be able to run custom images. (This vulnerability does not affect Docker due to an implementation detail that happens to block the attack.)

Sander Bos discovered Apport mishandled crash dumps originating from containers. This could be used by a local attacker to generate a crash report for a privileged process that is readable by an unprivileged user.

Multiple stack-based buffer overflows in net/netfilter/ipvs/ip_vs_ctl.c in the Linux kernel before 2.6.33, when CONFIG_IP_VS is used, allow local users to gain privileges by leveraging the CAP_NET_ADMIN capability for (1) a getsockopt system call, related to the do_ip_vs_get_ctl function, or (2) a setsockopt system call, related to the do_ip_vs_set_ctl function.

In the Linux kernel 4.19 through 5.6.7 on the s390 platform, code execution may occur because of a race condition, as demonstrated by code in enable_sacf_uaccess in arch/s390/lib/uaccess.c that fails to protect against a concurrent page table upgrade, aka CID-3f777e19d171. A crash could also occur.

arch/powerpc/mm/mmu_context_book3s64.c in the Linux kernel before 5.1.15 for powerpc has a bug where unrelated processes may be able to read/write to one another's virtual memory under certain conditions via an mmap above 512 TB. Only a subset of powerpc systems are affected.

In the Linux Kernel before version 4.16.11, 4.14.43, 4.9.102, and 4.4.133, multiple race condition errors when handling probe, disconnect, and rebind operations can be exploited to trigger a use-after-free condition or a NULL pointer dereference by sending multiple USB over IP packets.

A flaw use-after-free in function sco_sock_sendmsg() of the Linux kernel HCI subsystem was found in the way user calls ioct UFFDIO_REGISTER or other way triggers race condition of the call sco_conn_del() together with the call sco_sock_sendmsg() with the expected controllable faulting memory page. A privileged local user could use this flaw to crash the system or escalate their privileges on the system.

Insecure temporary file use in base-files

A potentially exploitable crash in TransportSecurityInfo used for SSL can be triggered by data stored in the local cache in the user profile directory. This issue is only exploitable in combination with another vulnerability allowing an attacker to write data into the local cache or from locally installed malware. This issue also triggers a non-exploitable startup crash for users switching between the Nightly and Release versions of Firefox if the same profile is used. This vulnerability affects Thunderbird < 60.2.1, Firefox ESR < 60.2.1, and Firefox < 62.0.2.

A flaw was found in the Linux Kernel where an attacker may be able to have an uncontrolled read to kernel-memory from within a vm guest. A race condition between connect() and close() function may allow an attacker using the AF_VSOCK protocol to gather a 4 byte information leak or possibly intercept or corrupt AF_VSOCK messages destined to other clients.

Apport contains a TOCTTOU vulnerability when reading the users ~/.apport-ignore.xml

init_tmp in TeeJee.FileSystem.vala in Timeshift before 20.03 unsafely reuses a preexisting temporary directory in the predictable location /tmp/timeshift. It follows symlinks in this location or uses directories owned by unprivileged users. Because Timeshift also executes scripts under this location, an attacker can attempt to win a race condition to replace scripts created by Timeshift with attacker-controlled scripts. Upon success, an attacker-controlled script is executed with full root privileges. This logic is practically always triggered when Timeshift runs regardless of the command-line arguments used.

A TOCTOU mismatch in the NFS client code in the Linux kernel before 5.8.3 could be used by local attackers to corrupt memory or possibly have unspecified other impact because a size check is in fs/nfs/nfs4proc.c instead of fs/nfs/nfs4xdr.c, aka CID-b4487b935452.

screenresolution-mechanism in screen-resolution-extra 0.17.2 does not properly use the PolicyKit D-Bus API, which allows local users to bypass intended access restrictions by leveraging a race condition via a setuid or pkexec process that is mishandled in a PolicyKitService._check_permission call.

The n_tty_write function in drivers/tty/n_tty.c in the Linux kernel through 3.14.3 does not properly manage tty driver access in the "LECHO & !OPOST" case, which allows local users to cause a denial of service (memory corruption and system crash) or gain privileges by triggering a race condition involving read and write operations with long strings.

The Linux kernel before 3.15.4 on Intel processors does not properly restrict use of a non-canonical value for the saved RIP address in the case of a system call that does not use IRET, which allows local users to leverage a race condition and gain privileges, or cause a denial of service (double fault), via a crafted application that makes ptrace and fork system calls.

There is an OS command injection vulnerability in Ruby Rake < 12.3.3 in Rake::FileList when supplying a filename that begins with the pipe character `|`.

The prepend_path function in fs/dcache.c in the Linux kernel before 4.2.4 does not properly handle rename actions inside a bind mount, which allows local users to bypass an intended container protection mechanism by renaming a directory, related to a "double-chroot attack."

Format string vulnerability in the b43_request_firmware function in drivers/net/wireless/b43/main.c in the Broadcom B43 wireless driver in the Linux kernel through 3.9.4 allows local users to gain privileges by leveraging root access and including format string specifiers in an fwpostfix modprobe parameter, leading to improper construction of an error message.

pam_motd (aka the MOTD module) in libpam-modules before 1.1.0-2ubuntu1.1 in PAM on Ubuntu 9.10 and libpam-modules before 1.1.1-2ubuntu5 in PAM on Ubuntu 10.04 LTS allows local users to change the ownership of arbitrary files via a symlink attack on .cache in a user's home directory, related to "user file stamps" and the motd.legal-notice file.

Heap-based buffer overflow in the wdm_in_callback function in drivers/usb/class/cdc-wdm.c in the Linux kernel before 3.8.4 allows physically proximate attackers to cause a denial of service (system crash) or possibly execute arbitrary code via a crafted cdc-wdm USB device.

Stack-based buffer overflow in the econet_sendmsg function in net/econet/af_econet.c in the Linux kernel before 2.6.36.2, when an econet address is configured, allows local users to gain privileges by providing a large number of iovec structures.

Buffer overflow in the picolcd_raw_event function in devices/hid/hid-picolcd_core.c in the PicoLCD HID device driver in the Linux kernel through 3.16.3, as used in Android on Nexus 7 devices, allows physically proximate attackers to cause a denial of service (system crash) or possibly execute arbitrary code via a crafted device that sends a large report.

soffice in OpenOffice.org (OOo) 3.x before 3.3 places a zero-length directory name in the LD_LIBRARY_PATH, which allows local users to gain privileges via a Trojan horse shared library in the current working directory.

An issue was discovered in the Linux kernel before 5.0.10. There is a use-after-free in the sound subsystem because card disconnection causes certain data structures to be deleted too early. This is related to sound/core/init.c and sound/core/info.c.

In the cron package through 3.0pl1-128 on Debian, and through 3.0pl1-128ubuntu2 on Ubuntu, the postinst maintainer script allows for group-crontab-to-root privilege escalation via symlink attacks against unsafe usage of the chown and chmod programs.