Vulnerabilities > CVE-2016-10318 - Permissions, Privileges, and Access Controls vulnerability in Linux Kernel
Attack vector
NETWORK Attack complexity
LOW Privileges required
LOW Confidentiality impact
NONE Integrity impact
NONE Availability impact
HIGH Summary
A missing authorization check in the fscrypt_process_policy function in fs/crypto/policy.c in the ext4 and f2fs filesystem encryption support in the Linux kernel before 4.7.4 allows a user to assign an encryption policy to a directory owned by a different user, potentially creating a denial of service.
Vulnerable Configurations
Common Weakness Enumeration (CWE)
Common Attack Pattern Enumeration and Classification (CAPEC)
- Accessing, Modifying or Executing Executable Files An attack of this type exploits a system's configuration that allows an attacker to either directly access an executable file, for example through shell access; or in a possible worst case allows an attacker to upload a file and then execute it. Web servers, ftp servers, and message oriented middleware systems which have many integration points are particularly vulnerable, because both the programmers and the administrators must be in synch regarding the interfaces and the correct privileges for each interface.
- Leverage Executable Code in Non-Executable Files An attack of this type exploits a system's trust in configuration and resource files, when the executable loads the resource (such as an image file or configuration file) the attacker has modified the file to either execute malicious code directly or manipulate the target process (e.g. application server) to execute based on the malicious configuration parameters. Since systems are increasingly interrelated mashing up resources from local and remote sources the possibility of this attack occurring is high. The attack can be directed at a client system, such as causing buffer overrun through loading seemingly benign image files, as in Microsoft Security Bulletin MS04-028 where specially crafted JPEG files could cause a buffer overrun once loaded into the browser. Another example targets clients reading pdf files. In this case the attacker simply appends javascript to the end of a legitimate url for a pdf (http://www.gnucitizen.org/blog/danger-danger-danger/) http://path/to/pdf/file.pdf#whatever_name_you_want=javascript:your_code_here The client assumes that they are reading a pdf, but the attacker has modified the resource and loaded executable javascript into the client's browser process. The attack can also target server processes. The attacker edits the resource or configuration file, for example a web.xml file used to configure security permissions for a J2EE app server, adding role name "public" grants all users with the public role the ability to use the administration functionality. The server trusts its configuration file to be correct, but when they are manipulated, the attacker gains full control.
- Blue Boxing This type of attack against older telephone switches and trunks has been around for decades. A tone is sent by an adversary to impersonate a supervisor signal which has the effect of rerouting or usurping command of the line. While the US infrastructure proper may not contain widespread vulnerabilities to this type of attack, many companies are connected globally through call centers and business process outsourcing. These international systems may be operated in countries which have not upgraded Telco infrastructure and so are vulnerable to Blue boxing. Blue boxing is a result of failure on the part of the system to enforce strong authorization for administrative functions. While the infrastructure is different than standard current applications like web applications, there are historical lessons to be learned to upgrade the access control for administrative functions.
- Restful Privilege Elevation Rest uses standard HTTP (Get, Put, Delete) style permissions methods, but these are not necessarily correlated generally with back end programs. Strict interpretation of HTTP get methods means that these HTTP Get services should not be used to delete information on the server, but there is no access control mechanism to back up this logic. This means that unless the services are properly ACL'd and the application's service implementation are following these guidelines then an HTTP request can easily execute a delete or update on the server side. The attacker identifies a HTTP Get URL such as http://victimsite/updateOrder, which calls out to a program to update orders on a database or other resource. The URL is not idempotent so the request can be submitted multiple times by the attacker, additionally, the attacker may be able to exploit the URL published as a Get method that actually performs updates (instead of merely retrieving data). This may result in malicious or inadvertent altering of data on the server.
- Target Programs with Elevated Privileges This attack targets programs running with elevated privileges. The attacker would try to leverage a bug in the running program and get arbitrary code to execute with elevated privileges. For instance an attacker would look for programs that write to the system directories or registry keys (such as HKLM, which stores a number of critical Windows environment variables). These programs are typically running with elevated privileges and have usually not been designed with security in mind. Such programs are excellent exploit targets because they yield lots of power when they break. The malicious user try to execute its code at the same level as a privileged system call.
Nessus
NASL family SuSE Local Security Checks NASL id OPENSUSE-2017-562.NASL description The openSUSE Leap 42.1 kernel was updated to receive various security and bugfixes. The following security bugs were fixed : - CVE-2017-7618: crypto/ahash.c in the Linux kernel allowed attackers to cause a denial of service (API operation calling its own callback, and infinite recursion) by triggering EBUSY on a full queue (bnc#1033340). - CVE-2016-10318: A missing authorization check in the fscrypt_process_policy function in fs/crypto/policy.c in the ext4 and f2fs filesystem encryption support in the Linux kernel allowed a user to assign an encryption policy to a directory owned by a different user, potentially creating a denial of service (bnc#1032435). - CVE-2017-7616: Incorrect error handling in the set_mempolicy and mbind compat syscalls in mm/mempolicy.c in the Linux kernel allowed local users to obtain sensitive information from uninitialized stack data by triggering failure of a certain bitmap operation (bnc#1033336). - CVE-2017-7308: The packet_set_ring function in net/packet/af_packet.c in the Linux kernel did not properly validate certain block-size data, which allowed local users to cause a denial of service (overflow) or possibly have unspecified other impact via crafted system calls (bnc#1031579). - CVE-2017-2671: The ping_unhash function in net/ipv4/ping.c in the Linux kernel is too late in obtaining a certain lock and consequently cannot ensure that disconnect function calls are safe, which allowed local users to cause a denial of service (panic) by leveraging access to the protocol value of IPPROTO_ICMP in a socket system call (bnc#1031003). - CVE-2017-7294: The vmw_surface_define_ioctl function in drivers/gpu/drm/vmwgfx/vmwgfx_surface.c in the Linux kernel did not validate addition of certain levels data, which allowed local users to trigger an integer overflow and out-of-bounds write, and cause a denial of service (system hang or crash) or possibly gain privileges, via a crafted ioctl call for a /dev/dri/renderD* device (bnc#1031440). - CVE-2017-7261: The vmw_surface_define_ioctl function in drivers/gpu/drm/vmwgfx/vmwgfx_surface.c in the Linux kernel did not check for a zero value of certain levels data, which allowed local users to cause a denial of service (ZERO_SIZE_PTR dereference, and GPF and possibly panic) via a crafted ioctl call for a /dev/dri/renderD* device (bnc#1031052). - CVE-2017-7187: The sg_ioctl function in drivers/scsi/sg.c in the Linux kernel allowed local users to cause a denial of service (stack-based buffer overflow) or possibly have unspecified other impact via a large command size in an SG_NEXT_CMD_LEN ioctl call, leading to out-of-bounds write access in the sg_write function (bnc#1030213). The following non-security bugs were fixed : - ata: ahci_xgene: free structure returned by acpi_get_object_info() (bsc#1033518). - doc/README.SUSE: update links to KMP manual - ext4: do not perform data journaling when data is encrypted (bsc#1012876). - ext4: fix use-after-iput when fscrypt contexts are inconsistent (bsc#1012829). - ext4: mark inode dirty after converting inline directory (bsc#1012876). - ext4: reject inodes with negative size (bsc#1012876). - fs, seqfile: always allow oom killer (bsc#1012876). - ipv6: make ECMP route replacement less greedy (bsc#930399). - l2tp: hold tunnel socket when handling control frames in l2tp_ip and l2tp_ip6 (bsc#1028415). - mm: filemap: do not plant shadow entries without radix tree node (bsc#1012876). - netfilter: allow logging from non-init namespaces (bsc#970083). - nfsd4: minor NFSv2/v3 write decoding cleanup (bsc#1034670 CVE#2017-7645). - nfsd: check for oversized NFSv2/v3 arguments (bsc#1034670 CVE#2017-7645). - nfsd: stricter decoding of write-like NFSv2/v3 ops (bsc#1034670 CVE#2017-7645). last seen 2020-06-05 modified 2017-05-09 plugin id 100044 published 2017-05-09 reporter This script is Copyright (C) 2017-2020 and is owned by Tenable, Inc. or an Affiliate thereof. source https://www.tenable.com/plugins/nessus/100044 title openSUSE Security Update : the Linux Kernel (openSUSE-2017-562) NASL family OracleVM Local Security Checks NASL id ORACLEVM_OVMSA-2017-0174.NASL description The remote OracleVM system is missing necessary patches to address critical security updates : please see Oracle VM Security Advisory OVMSA-2017-0174 for details. last seen 2020-06-05 modified 2017-12-14 plugin id 105248 published 2017-12-14 reporter This script is Copyright (C) 2017-2020 and is owned by Tenable, Inc. or an Affiliate thereof. source https://www.tenable.com/plugins/nessus/105248 title OracleVM 3.4 : Unbreakable / etc (OVMSA-2017-0174) (BlueBorne) (Dirty COW) (Stack Clash) NASL family OracleVM Local Security Checks NASL id ORACLEVM_OVMSA-2018-0035.NASL description The remote OracleVM system is missing necessary patches to address critical security updates : please see Oracle VM Security Advisory OVMSA-2018-0035 for details. last seen 2020-06-01 modified 2020-06-02 plugin id 109158 published 2018-04-19 reporter This script is Copyright (C) 2018-2019 and is owned by Tenable, Inc. or an Affiliate thereof. source https://www.tenable.com/plugins/nessus/109158 title OracleVM 3.4 : Unbreakable / etc (OVMSA-2018-0035) (Dirty COW) (Meltdown) (Spectre) NASL family Oracle Linux Local Security Checks NASL id ORACLELINUX_ELSA-2018-4071.NASL description The remote Oracle Linux host is missing a security update for the Unbreakable Enterprise kernel package(s). last seen 2020-06-01 modified 2020-06-02 plugin id 109156 published 2018-04-19 reporter This script is Copyright (C) 2018-2019 and is owned by Tenable, Inc. or an Affiliate thereof. source https://www.tenable.com/plugins/nessus/109156 title Oracle Linux 6 / 7 : Unbreakable Enterprise kernel (ELSA-2018-4071) (Dirty COW) (Meltdown) (Spectre) NASL family Huawei Local Security Checks NASL id EULEROS_SA-2019-1527.NASL description According to the versions of the kernel packages installed, the EulerOS Virtualization for ARM 64 installation on the remote host is affected by the following vulnerabilities : - The Linux kernel, before version 4.14.3, is vulnerable to a denial of service in drivers/md/dm.c:dm_get_from_kobject() which can be caused by local users leveraging a race condition with __dm_destroy() during creation and removal of DM devices. Only privileged local users (with CAP_SYS_ADMIN capability) can directly perform the ioctl operations for dm device creation and removal and this would typically be outside the direct control of the unprivileged attacker.(CVE-2017-18203i1/4%0 - The batadv_frag_merge_packets function in net/batman-adv/fragmentation.c in the B.A.T.M.A.N. implementation in the Linux kernel through 3.18.1 uses an incorrect length field during a calculation of an amount of memory, which allows remote attackers to cause a denial of service (mesh-node system crash) via fragmented packets.(CVE-2014-9428i1/4%0 - The regulator_ena_gpio_free function in drivers/regulator/core.c in the Linux kernel allows local users to gain privileges or cause a denial of service (use-after-free) via a crafted application.(CVE-2014-9940i1/4%0 - The Linux kernel before 3.12, when UDP Fragmentation Offload (UFO) is enabled, does not properly initialize certain data structures, which allows local users to cause a denial of service (memory corruption and system crash) or possibly gain privileges via a crafted application that uses the UDP_CORK option in a setsockopt system call and sends both short and long packets, related to the ip_ufo_append_data function in net/ipv4/ip_output.c and the ip6_ufo_append_data function in net/ipv6/ip6_output.c.(CVE-2013-4470i1/4%0 - A use-after-free flaw was found in the way the Linux kernel last seen 2020-03-19 modified 2019-05-14 plugin id 124980 published 2019-05-14 reporter This script is Copyright (C) 2019-2020 and is owned by Tenable, Inc. or an Affiliate thereof. source https://www.tenable.com/plugins/nessus/124980 title EulerOS Virtualization for ARM 64 3.0.1.0 : kernel (EulerOS-SA-2019-1527) NASL family Oracle Linux Local Security Checks NASL id ORACLELINUX_ELSA-2017-3659.NASL description The remote Oracle Linux host is missing a security update for the Unbreakable Enterprise kernel package(s). last seen 2020-06-05 modified 2017-12-14 plugin id 105247 published 2017-12-14 reporter This script is Copyright (C) 2017-2020 and is owned by Tenable, Inc. or an Affiliate thereof. source https://www.tenable.com/plugins/nessus/105247 title Oracle Linux 6 / 7 : Unbreakable Enterprise kernel (ELSA-2017-3659) (BlueBorne) (Dirty COW) (Stack Clash)
References
- http://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=163ae1c6ad6299b19e22b4a35d5ab24a89791a98
- http://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=163ae1c6ad6299b19e22b4a35d5ab24a89791a98
- http://www.kernel.org/pub/linux/kernel/v4.x/ChangeLog-4.7.4
- http://www.kernel.org/pub/linux/kernel/v4.x/ChangeLog-4.7.4
- http://www.securityfocus.com/bid/97404
- http://www.securityfocus.com/bid/97404
- https://github.com/torvalds/linux/commit/163ae1c6ad6299b19e22b4a35d5ab24a89791a98
- https://github.com/torvalds/linux/commit/163ae1c6ad6299b19e22b4a35d5ab24a89791a98