Linux

There is a vulnerability in the linux kernel versions higher than 5.2 (if kernel compiled with config params CONFIG_BPF_SYSCALL=y

CVE-2021-20194 7.8 - High - February 23, 2021

There is a vulnerability in the linux kernel versions higher than 5.2 (if kernel compiled with config params CONFIG_BPF_SYSCALL=y , CONFIG_BPF=y , CONFIG_CGROUPS=y , CONFIG_CGROUP_BPF=y , CONFIG_HARDENED_USERCOPY not set, and BPF hook to getsockopt is registered). As result of BPF execution, the local user can trigger bug in __cgroup_bpf_run_filter_getsockopt() function that can lead to heap overflow (because of non-hardened usercopy). The impact of attack could be deny of service or possibly privileges escalation.

CVE-2021-20194 is exploitable with local system access, and requires small amount of user privledges. This vulnerability is considered to have a low attack complexity. It has an exploitability score of 1.8 out of four. The potential impact of an exploit of this vulnerability is considered to be very high.

Improper Input Validation

A use-after-free flaw was found in the io_uring in Linux kernel, where a local attacker with a user privilege could cause a denial of service problem on the system The issue results

CVE-2021-20226 7.8 - High - February 23, 2021

A use-after-free flaw was found in the io_uring in Linux kernel, where a local attacker with a user privilege could cause a denial of service problem on the system The issue results from the lack of validating the existence of an object prior to performing operations on the object by not incrementing the file reference counter while in use. The highest threat from this vulnerability is to data integrity, confidentiality and system availability.

CVE-2021-20226 is exploitable with local system access, and requires small amount of user privledges. This vulnerability is considered to have a low attack complexity. It has an exploitability score of 1.8 out of four. The potential impact of an exploit of this vulnerability is considered to be very high.

Dangling pointer

A NULL pointer dereference flaw in Linux kernel versions prior to 5.11 may be seen if sco_sock_getsockopt function in net/bluetooth/sco.c do not have a sanity check for a socket connection

CVE-2020-35499 6.7 - Medium - February 19, 2021

A NULL pointer dereference flaw in Linux kernel versions prior to 5.11 may be seen if sco_sock_getsockopt function in net/bluetooth/sco.c do not have a sanity check for a socket connection, when using BT_SNDMTU/BT_RCVMTU for SCO sockets. This could allow a local attacker with a special user privilege to crash the system (DOS) or leak kernel internal information.

CVE-2020-35499 can be explotited with local system access, and requires user privledges. This vulnerability is considered to have a low attack complexity. It has an exploitability score of 0.8 out of four. The potential impact of an exploit of this vulnerability is considered to be very high.

NULL Pointer Dereference

An issue was discovered in the Linux kernel 3.2 through 5.10.16, as used by Xen

CVE-2021-26932 5.5 - Medium - February 17, 2021

An issue was discovered in the Linux kernel 3.2 through 5.10.16, as used by Xen. Grant mapping operations often occur in batch hypercalls, where a number of operations are done in a single hypercall, the success or failure of each one is reported to the backend driver, and the backend driver then loops over the results, performing follow-up actions based on the success or failure of each operation. Unfortunately, when running in PV mode, the Linux backend drivers mishandle this: Some errors are ignored, effectively implying their success from the success of related batch elements. In other cases, errors resulting from one batch element lead to further batch elements not being inspected, and hence successful ones to not be possible to properly unmap upon error recovery. Only systems with Linux backends running in PV mode are vulnerable. Linux backends run in HVM / PVH modes are not vulnerable. This affects arch/*/xen/p2m.c and drivers/xen/gntdev.c.

CVE-2021-26932 is exploitable with local system access, and requires small amount of user privledges. This vulnerability is considered to have a low attack complexity. It has an exploitability score of 1.8 out of four. The potential impact of an exploit of this vulnerability is considered to have no impact on confidentiality and integrity, and a high impact on availability.

An issue was discovered in the Linux kernel 4.18 through 5.10.16, as used by Xen

CVE-2021-26934 7.8 - High - February 17, 2021

An issue was discovered in the Linux kernel 4.18 through 5.10.16, as used by Xen. The backend allocation (aka be-alloc) mode of the drm_xen_front drivers was not meant to be a supported configuration, but this wasn't stated accordingly in its support status entry.

CVE-2021-26934 is exploitable with local system access, and requires small amount of user privledges. This vulnerability is considered to have a low attack complexity. It has an exploitability score of 1.8 out of four. The potential impact of an exploit of this vulnerability is considered to be very high.

An issue was discovered in the Linux kernel 2.6.39 through 5.10.16, as used in Xen

CVE-2021-26931 5.5 - Medium - February 17, 2021

An issue was discovered in the Linux kernel 2.6.39 through 5.10.16, as used in Xen. Block, net, and SCSI backends consider certain errors a plain bug, deliberately causing a kernel crash. For errors potentially being at least under the influence of guests (such as out of memory conditions), it isn't correct to assume a plain bug. Memory allocations potentially causing such crashes occur only when Linux is running in PV mode, though. This affects drivers/block/xen-blkback/blkback.c and drivers/xen/xen-scsiback.c.

CVE-2021-26931 can be explotited with local system access, and requires small amount of user privledges. This vulnerability is considered to have a low attack complexity. It has an exploitability score of 1.8 out of four. The potential impact of an exploit of this vulnerability is considered to have no impact on confidentiality and integrity, and a high impact on availability.

Allocation of Resources Without Limits or Throttling

An issue was discovered in the Linux kernel 3.11 through 5.10.16, as used by Xen

CVE-2021-26930 7.8 - High - February 17, 2021

An issue was discovered in the Linux kernel 3.11 through 5.10.16, as used by Xen. To service requests to the PV backend, the driver maps grant references provided by the frontend. In this process, errors may be encountered. In one case, an error encountered earlier might be discarded by later processing, resulting in the caller assuming successful mapping, and hence subsequent operations trying to access space that wasn't mapped. In another case, internal state would be insufficiently updated, preventing safe recovery from the error. This affects drivers/block/xen-blkback/blkback.c.

CVE-2021-26930 is exploitable with local system access, and requires small amount of user privledges. This vulnerability is considered to have a low attack complexity. It has an exploitability score of 1.8 out of four. The potential impact of an exploit of this vulnerability is considered to be very high.

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

CVE-2020-16120 4.4 - Medium - February 10, 2021

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.

CVE-2020-16120 is exploitable with local system access, and requires user privledges. This vulnerability is considered to have a low attack complexity. It has an exploitability score of 0.8 out of four. The potential impact of an exploit of this vulnerability is considered to have a high impact on confidentiality, with no impact on integrity and availability.

Improper Privilege Management

A local privilege escalation was discovered in the Linux kernel before 5.10.13

CVE-2021-26708 7 - High - February 05, 2021

A local privilege escalation was discovered in the Linux kernel before 5.10.13. Multiple race conditions in the AF_VSOCK implementation are caused by wrong locking in net/vmw_vsock/af_vsock.c. The race conditions were implicitly introduced in the commits that added VSOCK multi-transport support.

CVE-2021-26708 is exploitable with local system access, and requires small amount of user privledges. This vulnerability is consided to have a high level of attack complexity. It has an exploitability score of 1.0 out of four. The potential impact of an exploit of this vulnerability is considered to be very high.

Improper Privilege Management

nbd_add_socket in drivers/block/nbd.c in the Linux kernel through 5.10.12 has an ndb_queue_rq use-after-free

CVE-2021-3348 7 - High - February 01, 2021

nbd_add_socket in drivers/block/nbd.c in the Linux kernel through 5.10.12 has an ndb_queue_rq use-after-free that could be triggered by local attackers (with access to the nbd device) via an I/O request at a certain point during device setup, aka CID-b98e762e3d71.

CVE-2021-3348 is exploitable with local system access, and requires small amount of user privledges. This vulnerability is consided to have a high level of attack complexity. It has an exploitability score of 1.0 out of four. The potential impact of an exploit of this vulnerability is considered to be very high.

Race Condition

An issue was discovered in the Linux kernel through 5.10.11

CVE-2021-3347 7.8 - High - January 29, 2021

An issue was discovered in the Linux kernel through 5.10.11. PI futexes have a kernel stack use-after-free during fault handling, allowing local users to execute code in the kernel, aka CID-34b1a1ce1458.

CVE-2021-3347 can be explotited with local system access, and requires small amount of user privledges. This vulnerability is considered to have a low attack complexity. It has an exploitability score of 1.8 out of four. The potential impact of an exploit of this vulnerability is considered to be very high.

Dangling pointer

A flaw incorrect umask during file or directory modification in the Linux kernel NFS (network file system) functionality was found in the way user create and delete object using NFSv4.2 or newer if both simultaneously accessing the NFS by the other process

CVE-2020-35513 4.9 - Medium - January 26, 2021

A flaw incorrect umask during file or directory modification in the Linux kernel NFS (network file system) functionality was found in the way user create and delete object using NFSv4.2 or newer if both simultaneously accessing the NFS by the other process that is not using new NFSv4.2. A user with access to the NFS could use this flaw to starve the resources causing denial of service.

CVE-2020-35513 can be explotited with network access, and requires user privledges. This vulnerability is considered to have a low attack complexity. It has an exploitability score of 1.2 out of four. The potential impact of an exploit of this vulnerability is considered to have no impact on confidentiality and integrity, and a high impact on availability.

Privilege Dropping / Lowering Errors

** DISPUTED ** fs/nfsd/nfs3xdr.c in the Linux kernel through 5.10.8, when there is an NFS export of a subdirectory of a filesystem

CVE-2021-3178 6.5 - Medium - January 19, 2021

** DISPUTED ** fs/nfsd/nfs3xdr.c in the Linux kernel through 5.10.8, when there is an NFS export of a subdirectory of a filesystem, allows remote attackers to traverse to other parts of the filesystem via READDIRPLUS. NOTE: some parties argue that such a subdirectory export is not intended to prevent this attack; see also the exports(5) no_subtree_check default behavior.

CVE-2021-3178 is exploitable with network access, and requires user privledges. This vulnerability is considered to have a low attack complexity. It has an exploitability score of 1.2 out of four. The potential impact of an exploit of this vulnerability is considered to have a high impact on confidentiality and integrity, and no impact on availability.

Directory traversal

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

CVE-2020-16119 7.8 - High - January 14, 2021

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.

CVE-2020-16119 can be explotited with local system access, and requires small amount of user privledges. This vulnerability is considered to have a low attack complexity. It has an exploitability score of 1.8 out of four. The potential impact of an exploit of this vulnerability is considered to be very high.

Dangling pointer

In drivers/target/target_core_xcopy.c in the Linux kernel before 5.10.7, insufficient identifier checking in the LIO SCSI target code can be used by remote attackers to read or write files

CVE-2020-28374 8.1 - High - January 13, 2021

In drivers/target/target_core_xcopy.c in the Linux kernel before 5.10.7, insufficient identifier checking in the LIO SCSI target code can be used by remote attackers to read or write files via directory traversal in an XCOPY request, aka CID-2896c93811e3. For example, an attack can occur over a network if the attacker has access to one iSCSI LUN. The attacker gains control over file access because I/O operations are proxied via an attacker-selected backstore.

CVE-2020-28374 is exploitable with network access, and requires small amount of user privledges. This vulnerability is considered to have a low attack complexity. It has an exploitability score of 2.8 out of four. The potential impact of an exploit of this vulnerability is considered to have a high impact on confidentiality and integrity, and no impact on availability.

Directory traversal

mwifiex_cmd_802_11_ad_hoc_start in drivers/net/wireless/marvell/mwifiex/join.c in the Linux kernel through 5.10.4 might

CVE-2020-36158 6.7 - Medium - January 05, 2021

mwifiex_cmd_802_11_ad_hoc_start in drivers/net/wireless/marvell/mwifiex/join.c in the Linux kernel through 5.10.4 might allow remote attackers to execute arbitrary code via a long SSID value, aka CID-5c455c5ab332.

CVE-2020-36158 is exploitable with local system access, and requires user privledges. This vulnerability is considered to have a low attack complexity. It has an exploitability score of 0.8 out of four. The potential impact of an exploit of this vulnerability is considered to be very high.

buffer overrun

A flaw was found in the way RTAS handled memory accesses in userspace to kernel communication

CVE-2020-27777 6.7 - Medium - December 15, 2020

A flaw was found in the way RTAS handled memory accesses in userspace to kernel communication. On a locked down (usually due to Secure Boot) guest system running on top of PowerVM or KVM hypervisors (pseries platform) a root like local user could use this flaw to further increase their privileges to that of a running kernel.

CVE-2020-27777 can be explotited with local system access, and requires user privledges. This vulnerability is considered to have a low attack complexity. It has an exploitability score of 0.8 out of four. The potential impact of an exploit of this vulnerability is considered to be very high.

AuthZ

An issue was discovered in the Linux kernel through 5.10.1, as used with Xen through 4.14.x

CVE-2020-29569 8.8 - High - December 15, 2020

An issue was discovered in the Linux kernel through 5.10.1, as used with Xen through 4.14.x. The Linux kernel PV block backend expects the kernel thread handler to reset ring->xenblkd to NULL when stopped. However, the handler may not have time to run if the frontend quickly toggles between the states connect and disconnect. As a consequence, the block backend may re-use a pointer after it was freed. A misbehaving guest can trigger a dom0 crash by continuously connecting / disconnecting a block frontend. Privilege escalation and information leaks cannot be ruled out. This only affects systems with a Linux blkback.

CVE-2020-29569 can be explotited with local system access, and requires small amount of user privledges. This vulnerability is considered to have a low attack complexity. It has an exploitability score of 2.0 out of four. The potential impact of an exploit of this vulnerability is considered to be very high.

Unchecked Return Value

A use-after-free flaw was found in kernel/trace/ring_buffer.c in Linux kernel (before 5.10-rc1)

CVE-2020-27825 5.7 - Medium - December 11, 2020

A use-after-free flaw was found in kernel/trace/ring_buffer.c in Linux kernel (before 5.10-rc1). There was a race problem in trace_open and resize of cpu buffer running parallely on different cpus, may cause a denial of service problem (DOS). This flaw could even allow a local attacker with special user privilege to a kernel information leak threat.

CVE-2020-27825 can be explotited with local system access, and requires user privledges. This vulnerability is consided to have a high level of attack complexity. It has an exploitability score of 0.5 out of four. The potential impact of an exploit of this vulnerability is considered to have a high impact on confidentiality, with no impact on integrity, and a high impact on availability.

Race Condition

A flaw was found in the Linux kernels implementation of MIDI

CVE-2020-27786 7.8 - High - December 11, 2020

A flaw was found in the Linux kernels implementation of MIDI, where an attacker with a local account and the permissions to issue an ioctl commands to midi devices, could trigger a use-after-free. A write to this specific memory while freed and before use could cause the flow of execution to change and possibly allow for memory corruption or privilege escalation.

CVE-2020-27786 is exploitable with local system access, and requires small amount of user privledges. This vulnerability is considered to have a low attack complexity. It has an exploitability score of 1.8 out of four. The potential impact of an exploit of this vulnerability is considered to be very high.

Dangling pointer