EulerOS 2.0 SP9 : kernel (EulerOS-SA-2021-1950)

high Nessus Plugin ID 150213

Synopsis

The remote EulerOS host is missing multiple security updates.

Description

According to the versions of the kernel packages installed, the EulerOS installation on the remote host is affected by the following vulnerabilities :

 - An issue was discovered in the Linux kernel through 5.11.3. A kernel pointer leak can be used to determine the address of the iscsi_transport structure. When an iSCSI transport is registered with the iSCSI subsystem, the transport's handle is available to unprivileged users via the sysfs file system, at /sys/class/iscsi_transport/$TRANSPORT_NAME/handle. When read, the show_transport_handle function (in drivers/scsi/scsi_transport_iscsi.c) is called, which leaks the handle. This handle is actually the pointer to an iscsi_transport struct in the kernel module's global variables.(CVE-2021-27363)

 - An issue was discovered in the Linux kernel through 5.11.3. Certain iSCSI data structures do not have appropriate length constraints or checks, and can exceed the PAGE_SIZE value. An unprivileged user can send a Netlink message that is associated with iSCSI, and has a length up to the maximum length of a Netlink message.(CVE-2021-27365)

 - 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.(CVE-2021-27364)

 - 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)

 - A flaw was found in the Linux kernel's implementation of string matching within a packet. A privileged user (with root or CAP_NET_ADMIN) when inserting iptables rules could insert a rule which can panic the system.(CVE-2021-20177)

 - 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)

 - 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)

 - 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)

Note that Tenable Network Security has extracted the preceding description block directly from the EulerOS security advisory. Tenable has attempted to automatically clean and format it as much as possible without introducing additional issues.

Solution

Update the affected kernel packages.

See Also

http://www.nessus.org/u?8fb2b21a

Plugin Details

Severity: High

ID: 150213

File Name: EulerOS_SA-2021-1950.nasl

Version: 1.2

Type: local

Published: 6/3/2021

Updated: 6/7/2021

Risk Information

VPR

Risk Factor: Critical

Score: 9.0

CVSS v2

Risk Factor: High

Base Score: 7.2

Temporal Score: 5.3

Vector: CVSS2#AV:L/AC:L/Au:N/C:C/I:C/A:C

Temporal Vector: CVSS2#E:U/RL:OF/RC:C

CVSS v3

Risk Factor: High

Base Score: 7.8

Temporal Score: 6.8

Vector: CVSS:3.0/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Temporal Vector: CVSS:3.0/E:U/RL:O/RC:C

Vulnerability Information

CPE: p-cpe:/a:huawei:euleros:kernel, p-cpe:/a:huawei:euleros:kernel-tools, p-cpe:/a:huawei:euleros:kernel-tools-libs, p-cpe:/a:huawei:euleros:python3-perf, cpe:/o:huawei:euleros:2.0

Required KB Items: Host/local_checks_enabled, Host/EulerOS/release, Host/EulerOS/rpm-list, Host/EulerOS/sp

Exploit Ease: No known exploits are available

Patch Publication Date: 6/2/2021

Reference Information

CVE: CVE-2020-16120, CVE-2021-20177, CVE-2021-27363, CVE-2021-27364, CVE-2021-27365, CVE-2021-3178, CVE-2021-3347, CVE-2021-3348