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-14 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-13 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-8 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-lts package apport hooks, it could expose private data to other local users.

The io_uring subsystem in the Linux kernel allowed the MAX_RW_COUNT limit to be bypassed in the PROVIDE_BUFFERS operation, which led to negative values being usedin mem_rw when reading /proc/<PID>/mem. This could be used to create a heap overflow leading to arbitrary code execution in the kernel. It was addressed via commit d1f82808877b ("io_uring: truncate lengths larger than MAX_RW_COUNT on provide buffers") (v5.13-rc1) and backported to the stable kernels in v5.12.4, v5.11.21, and v5.10.37. It was introduced in ddf0322db79c ("io_uring: add IORING_OP_PROVIDE_BUFFERS") (v5.7-rc1).

The eBPF ALU32 bounds tracking for bitwise ops (AND, OR and XOR) in the Linux kernel did not properly update 32-bit bounds, which could be turned into out of bounds reads and writes in the Linux kernel and therefore, arbitrary code execution. This issue was fixed via commit 049c4e13714e ("bpf: Fix alu32 const subreg bound tracking on bitwise operations") (v5.13-rc4) and backported to the stable kernels in v5.12.4, v5.11.21, and v5.10.37. The AND/OR issues were introduced by commit 3f50f132d840 ("bpf: Verifier, do explicit ALU32 bounds tracking") (5.7-rc1) and the XOR variant was introduced by 2921c90d4718 ("bpf:Fix a verifier failure with xor") ( 5.10-rc1).

The eBPF RINGBUF bpf_ringbuf_reserve() function in the Linux kernel did not check that the allocated size was smaller than the ringbuf size, allowing an attacker to perform out-of-bounds writes within the kernel and therefore, arbitrary code execution. This issue was fixed via commit 4b81ccebaeee ("bpf, ringbuf: Deny reserve of buffers larger than ringbuf") (v5.13-rc4) and backported to the stable kernels in v5.12.4, v5.11.21, and v5.10.37. It was introduced via 457f44363a88 ("bpf: Implement BPF ring buffer and verifier support for it") (v5.8-rc1).

OpenVPN 2.5.1 and earlier versions allows a remote attackers to bypass authentication and access control channel data on servers configured with deferred authentication, which can be used to potentially trigger further information leaks.

The bpf verifier in the Linux kernel did not properly handle mod32 destination register truncation when the source register was known to be 0. A local attacker with the ability to load bpf programs could use this gain out-of-bounds reads in kernel memory leading to information disclosure (kernel memory), and possibly out-of-bounds writes that could potentially lead to code execution. This issue was addressed in the upstream kernel in commit 9b00f1b78809 ("bpf: Fix truncation handling for mod32 dst reg wrt zero") and in Linux stable kernels 5.11.2, 5.10.19, and 5.4.101.

An issue was discovered in the Linux kernel before 5.11.8. kernel/bpf/verifier.c has an off-by-one error (with a resultant integer underflow) affecting out-of-bounds speculation on pointer arithmetic, leading to side-channel attacks that defeat Spectre mitigations and obtain sensitive information from kernel memory, aka CID-10d2bb2e6b1d.

An issue was discovered in the Linux kernel before 5.11.8. kernel/bpf/verifier.c performs undesirable out-of-bounds speculation on pointer arithmetic, leading to side-channel attacks that defeat Spectre mitigations and obtain sensitive information from kernel memory, aka CID-f232326f6966. This affects pointer types that do not define a ptr_limit.

An issue was discovered in the Linux kernel through 5.11.3. drivers/scsi/scsi_transport_iscsi.c is adversely affected by the ability of an unprivileged user to craft Netlink messages.

Overlayfs did not properly perform permission checking when copying up files in an overlayfs and could be exploited from within a user namespace, if, for example, unprivileged user namespaces were allowed. It was possible to have a file not readable by an unprivileged user to be copied to a mountpoint controlled by the user, like a removable device. This was introduced in kernel version 4.19 by commit d1d04ef ("ovl: stack file ops"). This was fixed in kernel version 5.8 by commits 56230d9 ("ovl: verify permissions in ovl_path_open()"), 48bd024 ("ovl: switch to mounter creds in readdir") and 05acefb ("ovl: check permission to open real file"). Additionally, commits 130fdbc ("ovl: pass correct flags for opening real directory") and 292f902 ("ovl: call secutiry hook in ovl_real_ioctl()") in kernel 5.8 might also be desired or necessary. These additional commits introduced a regression in overlay mounts within user namespaces which prevented access to files with ownership outside of the user namespace. This regression was mitigated by subsequent commit b6650da ("ovl: do not fail because of O_NOATIMEi") in kernel 5.11.

Use-after-free vulnerability in the Linux kernel exploitable by a local attacker due to reuse of a DCCP socket with an attached dccps_hc_tx_ccid object as a listener after being released. Fixed in Ubuntu Linux kernel 5.4.0-51.56, 5.3.0-68.63, 4.15.0-121.123, 4.4.0-193.224, 3.13.0.182.191 and 3.2.0-149.196.

GNOME gdk-pixbuf (aka GdkPixbuf) before 2.42.2 allows a denial of service (infinite loop) in lzw.c in the function write_indexes. if c->self_code equals 10, self->code_table[10].extends will assign the value 11 to c. The next execution in the loop will assign self->code_table[11].extends to c, which will give the value of 10. This will make the loop run infinitely. This bug can, for example, be triggered by calling this function with a GIF image with LZW compression that is crafted in a special way.

Various memory and file descriptor leaks were found in apt-python files python/arfile.cc, python/tag.cc, python/tarfile.cc, aka GHSL-2020-170. This issue affects: python-apt 1.1.0~beta1 versions prior to 1.1.0~beta1ubuntu0.16.04.10; 1.6.5ubuntu0 versions prior to 1.6.5ubuntu0.4; 2.0.0ubuntu0 versions prior to 2.0.0ubuntu0.20.04.2; 2.1.3ubuntu1 versions prior to 2.1.3ubuntu1.1;

APT had several integer overflows and underflows while parsing .deb packages, aka GHSL-2020-168 GHSL-2020-169, in files apt-pkg/contrib/extracttar.cc, apt-pkg/deb/debfile.cc, and apt-pkg/contrib/arfile.cc. This issue affects: apt 1.2.32ubuntu0 versions prior to 1.2.32ubuntu0.2; 1.6.12ubuntu0 versions prior to 1.6.12ubuntu0.2; 2.0.2ubuntu0 versions prior to 2.0.2ubuntu0.2; 2.1.10ubuntu0 versions prior to 2.1.10ubuntu0.1;

Aptdaemon performed policykit checks after interacting with potentially untrusted files with elevated privileges. This affected versions prior to 1.1.1+bzr982-0ubuntu34.1, 1.1.1+bzr982-0ubuntu32.3, 1.1.1+bzr982-0ubuntu19.5, 1.1.1+bzr982-0ubuntu14.5.

The aptdaemon DBus interface disclosed file existence disclosure by setting Terminal/DebconfSocket properties, aka GHSL-2020-192 and GHSL-2020-196. This affected versions prior to 1.1.1+bzr982-0ubuntu34.1, 1.1.1+bzr982-0ubuntu32.3, 1.1.1+bzr982-0ubuntu19.5, 1.1.1+bzr982-0ubuntu14.5.

An Ubuntu-specific patch in PulseAudio created a race condition where the snap policy module would fail to identify a client connection from a snap as coming from a snap if SCM_CREDENTIALS were missing, allowing the snap to connect to PulseAudio without proper confinement. This could be exploited by an attacker to expose sensitive information. Fixed in 1:13.99.3-1ubuntu2, 1:13.99.2-1ubuntu2.1, 1:13.99.1-1ubuntu3.8, 1:11.1-1ubuntu7.11, and 1:8.0-0ubuntu3.15.