Vulnerabilities > CVE-2016-6259 - Improper Input Validation vulnerability in multiple products
Attack vector
LOCAL Attack complexity
LOW Privileges required
NONE Confidentiality impact
NONE Integrity impact
NONE Availability impact
HIGH Summary
Xen 4.5.x through 4.7.x do not implement Supervisor Mode Access Prevention (SMAP) whitelisting in 32-bit exception and event delivery, which allows local 32-bit PV guest OS kernels to cause a denial of service (hypervisor and VM crash) by triggering a safety check.
Vulnerable Configurations
Part | Description | Count |
---|---|---|
OS | 8 | |
Application | 6 |
Common Weakness Enumeration (CWE)
Common Attack Pattern Enumeration and Classification (CAPEC)
- Buffer Overflow via Environment Variables This attack pattern involves causing a buffer overflow through manipulation of environment variables. Once the attacker finds that they can modify an environment variable, they may try to overflow associated buffers. This attack leverages implicit trust often placed in environment variables.
- Server Side Include (SSI) Injection An attacker can use Server Side Include (SSI) Injection to send code to a web application that then gets executed by the web server. Doing so enables the attacker to achieve similar results to Cross Site Scripting, viz., arbitrary code execution and information disclosure, albeit on a more limited scale, since the SSI directives are nowhere near as powerful as a full-fledged scripting language. Nonetheless, the attacker can conveniently gain access to sensitive files, such as password files, and execute shell commands.
- Cross Zone Scripting An attacker is able to cause a victim to load content into their web-browser that bypasses security zone controls and gain access to increased privileges to execute scripting code or other web objects such as unsigned ActiveX controls or applets. This is a privilege elevation attack targeted at zone-based web-browser security. In a zone-based model, pages belong to one of a set of zones corresponding to the level of privilege assigned to that page. Pages in an untrusted zone would have a lesser level of access to the system and/or be restricted in the types of executable content it was allowed to invoke. In a cross-zone scripting attack, a page that should be assigned to a less privileged zone is granted the privileges of a more trusted zone. This can be accomplished by exploiting bugs in the browser, exploiting incorrect configuration in the zone controls, through a cross-site scripting attack that causes the attackers' content to be treated as coming from a more trusted page, or by leveraging some piece of system functionality that is accessible from both the trusted and less trusted zone. This attack differs from "Restful Privilege Escalation" in that the latter correlates to the inadequate securing of RESTful access methods (such as HTTP DELETE) on the server, while cross-zone scripting attacks the concept of security zones as implemented by a browser.
- Cross Site Scripting through Log Files An attacker may leverage a system weakness where logs are susceptible to log injection to insert scripts into the system's logs. If these logs are later viewed by an administrator through a thin administrative interface and the log data is not properly HTML encoded before being written to the page, the attackers' scripts stored in the log will be executed in the administrative interface with potentially serious consequences. This attack pattern is really a combination of two other attack patterns: log injection and stored cross site scripting.
- Command Line Execution through SQL Injection An attacker uses standard SQL injection methods to inject data into the command line for execution. This could be done directly through misuse of directives such as MSSQL_xp_cmdshell or indirectly through injection of data into the database that would be interpreted as shell commands. Sometime later, an unscrupulous backend application (or could be part of the functionality of the same application) fetches the injected data stored in the database and uses this data as command line arguments without performing proper validation. The malicious data escapes that data plane by spawning new commands to be executed on the host.
Nessus
NASL family Misc. NASL id CITRIX_XENSERVER_CTX214954.NASL description The version of Citrix XenServer running on the remote host is missing a security hotfix. It is, therefore, affected by multiple vulnerabilities : - A privilege escalation vulnerability known as last seen 2020-06-01 modified 2020-06-02 plugin id 92723 published 2016-08-04 reporter This script is Copyright (C) 2016-2019 and is owned by Tenable, Inc. or an Affiliate thereof. source https://www.tenable.com/plugins/nessus/92723 title Citrix XenServer Multiple Vulnerabilities (CTX214954) (Bunker Buster) NASL family FreeBSD Local Security Checks NASL id FREEBSD_PKG_04CF89E3585411E6B334002590263BF5.NASL description The Xen Project reports : Supervisor Mode Access Prevention is a hardware feature designed to make an Operating System more robust, by raising a pagefault rather than accidentally following a pointer into userspace. However, legitimate accesses into userspace require whitelisting, and the exception delivery mechanism for 32bit PV guests wasn last seen 2020-06-01 modified 2020-06-02 plugin id 92675 published 2016-08-02 reporter This script is Copyright (C) 2016-2019 and is owned by Tenable, Inc. or an Affiliate thereof. source https://www.tenable.com/plugins/nessus/92675 title FreeBSD : xen-kernel -- x86: Missing SMAP whitelisting in 32-bit exception / event delivery (04cf89e3-5854-11e6-b334-002590263bf5) NASL family Fedora Local Security Checks NASL id FEDORA_2016-01CC766201.NASL description x86: Privilege escalation in PV guests [XSA-182, CVE-2016-6258] x86: Missing SMAP whitelisting in 32-bit exception / event delivery [XSA-183, CVE-2016-6259] virtio: unbounded memory allocation issue [XSA-184, CVE-2016-5403] Qemu: scsi: esp: OOB write access in esp_do_dma [CVE-2016-6351] Note that Tenable Network Security has extracted the preceding description block directly from the Fedora update system website. Tenable has attempted to automatically clean and format it as much as possible without introducing additional issues. last seen 2020-06-05 modified 2016-08-08 plugin id 92766 published 2016-08-08 reporter This script is Copyright (C) 2016-2020 and is owned by Tenable, Inc. or an Affiliate thereof. source https://www.tenable.com/plugins/nessus/92766 title Fedora 24 : xen (2016-01cc766201) (Bunker Buster) NASL family SuSE Local Security Checks NASL id SUSE_SU-2016-2093-1.NASL description This update for xen to version 4.5.3 fixes the several issues. These security issues were fixed : - CVE-2016-6258: Potential privilege escalation in PV guests (XSA-182) (bsc#988675). - CVE-2016-6259: Missing SMAP whitelisting in 32-bit exception / event delivery (XSA-183) (bsc#988676). - CVE-2016-5337: The megasas_ctrl_get_info function allowed local guest OS administrators to obtain sensitive host memory information via vectors related to reading device control information (bsc#983973). - CVE-2016-5338: The (1) esp_reg_read and (2) esp_reg_write functions allowed local guest OS administrators to cause a denial of service (QEMU process crash) or execute arbitrary code on the host via vectors related to the information transfer buffer (bsc#983984). - CVE-2016-5238: The get_cmd function in hw/scsi/esp.c might have allowed local guest OS administrators to cause a denial of service (out-of-bounds write and QEMU process crash) via vectors related to reading from the information transfer buffer in non-DMA mode (bsc#982960). - CVE-2016-4453: The vmsvga_fifo_run function allowed local guest OS administrators to cause a denial of service (infinite loop and QEMU process crash) via a VGA command (bsc#982225). - CVE-2016-4454: The vmsvga_fifo_read_raw function allowed local guest OS administrators to obtain sensitive host memory information or cause a denial of service (QEMU process crash) by changing FIFO registers and issuing a VGA command, which triggered an out-of-bounds read (bsc#982224). - CVE-2016-5126: Heap-based buffer overflow in the iscsi_aio_ioctl function allowed local guest OS users to cause a denial of service (QEMU process crash) or possibly execute arbitrary code via a crafted iSCSI asynchronous I/O ioctl call (bsc#982286). - CVE-2016-5105: Stack information leakage while reading configuration (bsc#982024). - CVE-2016-5106: Out-of-bounds write while setting controller properties (bsc#982025). - CVE-2016-5107: Out-of-bounds read in megasas_lookup_frame() function (bsc#982026). - CVE-2016-4963: The libxl device-handling allowed local guest OS users with access to the driver domain to cause a denial of service (management tool confusion) by manipulating information in the backend directories in xenstore (bsc#979670). - CVE-2016-4962: The libxl device-handling allowed local OS guest administrators to cause a denial of service (resource consumption or management facility confusion) or gain host OS privileges by manipulating information in guest controlled areas of xenstore (bsc#979620). - CVE-2016-4952: Out-of-bounds access issue in pvsci_ring_init_msg/data routines (bsc#981276). - CVE-2014-3672: The qemu implementation in libvirt Xen allowed local guest OS users to cause a denial of service (host disk consumption) by writing to stdout or stderr (bsc#981264). - CVE-2016-4441: The get_cmd function in the 53C9X Fast SCSI Controller (FSC) support did not properly check DMA length, which allowed local guest OS administrators to cause a denial of service (out-of-bounds write and QEMU process crash) via unspecified vectors, involving an SCSI command (bsc#980724). - CVE-2016-4439: The esp_reg_write function in the 53C9X Fast SCSI Controller (FSC) support did not properly check command buffer length, which allowed local guest OS administrators to cause a denial of service (out-of-bounds write and QEMU process crash) or potentially execute arbitrary code on the host via unspecified vectors (bsc#980716). - CVE-2016-3710: The VGA module improperly performed bounds checking on banked access to video memory, which allowed local guest OS administrators to execute arbitrary code on the host by changing access modes after setting the bank register, aka the last seen 2020-06-01 modified 2020-06-02 plugin id 93296 published 2016-09-02 reporter This script is Copyright (C) 2016-2019 and is owned by Tenable, Inc. or an Affiliate thereof. source https://www.tenable.com/plugins/nessus/93296 title SUSE SLED12 / SLES12 Security Update : xen (SUSE-SU-2016:2093-1) (Bunker Buster) NASL family Fedora Local Security Checks NASL id FEDORA_2016-0049AA6E5D.NASL description x86: Privilege escalation in PV guests [XSA-182, CVE-2016-6258] x86: Missing SMAP whitelisting in 32-bit exception / event delivery [XSA-183, CVE-2016-6259] virtio: unbounded memory allocation issue [XSA-184, CVE-2016-5403] Qemu: scsi: esp: OOB write access in esp_do_dma [CVE-2016-6351] Note that Tenable Network Security has extracted the preceding description block directly from the Fedora update system website. Tenable has attempted to automatically clean and format it as much as possible without introducing additional issues. last seen 2020-06-05 modified 2016-08-09 plugin id 92796 published 2016-08-09 reporter This script is Copyright (C) 2016-2020 and is owned by Tenable, Inc. or an Affiliate thereof. source https://www.tenable.com/plugins/nessus/92796 title Fedora 23 : xen (2016-0049aa6e5d) (Bunker Buster) NASL family SuSE Local Security Checks NASL id OPENSUSE-2016-1170.NASL description This update for xen fixes the following issues : These security issues were fixed : - CVE-2016-7092: The get_page_from_l3e function in arch/x86/mm.c in Xen allowed local 32-bit PV guest OS administrators to gain host OS privileges via vectors related to L3 recursive pagetables (bsc#995785) - CVE-2016-7093: Xen allowed local HVM guest OS administrators to overwrite hypervisor memory and consequently gain host OS privileges by leveraging mishandling of instruction pointer truncation during emulation (bsc#995789) - CVE-2016-7094: Buffer overflow in Xen allowed local x86 HVM guest OS administrators on guests running with shadow paging to cause a denial of service via a pagetable update (bsc#995792) - CVE-2016-6836: VMWARE VMXNET3 NIC device support was leaging information leakage. A privileged user inside guest could have used this to leak host memory bytes to a guest (boo#994761) - CVE-2016-6888: Integer overflow in packet initialisation in VMXNET3 device driver. A privileged user inside guest could have used this flaw to crash the Qemu instance resulting in DoS (bsc#994772) - CVE-2016-6833: Use-after-free issue in the VMWARE VMXNET3 NIC device support. A privileged user inside guest could have used this issue to crash the Qemu instance resulting in DoS (boo#994775) - CVE-2016-6835: Buffer overflow in the VMWARE VMXNET3 NIC device support, causing an OOB read access (bsc#994625) - CVE-2016-6834: A infinite loop during packet fragmentation in the VMWARE VMXNET3 NIC device support allowed privileged user inside guest to crash the Qemu instance resulting in DoS (bsc#994421) - CVE-2016-6258: The PV pagetable code in arch/x86/mm.c in Xen allowed local 32-bit PV guest OS administrators to gain host OS privileges by leveraging fast-paths for updating pagetable entries (bsc#988675) - CVE-2016-6259: Xen did not implement Supervisor Mode Access Prevention (SMAP) whitelisting in 32-bit exception and event delivery, which allowed local 32-bit PV guest OS kernels to cause a denial of service (hypervisor and VM crash) by triggering a safety check (bsc#988676) - CVE-2016-5403: The virtqueue_pop function in hw/virtio/virtio.c in QEMU allowed local guest OS administrators to cause a denial of service (memory consumption and QEMU process crash) by submitting requests without waiting for completion (boo#990923) - CVE-2016-6351: The esp_do_dma function in hw/scsi/esp.c, when built with ESP/NCR53C9x controller emulation support, allowed local guest OS administrators to cause a denial of service (out-of-bounds write and QEMU process crash) or execute arbitrary code on the host via vectors involving DMA read into ESP command buffer (bsc#990843) - CVE-2016-6258: The PV pagetable code in arch/x86/mm.c in Xen allowed local 32-bit PV guest OS administrators to gain host OS privileges by leveraging fast-paths for updating pagetable entries (bsc#988675) - CVE-2016-6259: Xen did not implement Supervisor Mode Access Prevention (SMAP) whitelisting in 32-bit exception and event delivery, which allowed local 32-bit PV guest OS kernels to cause a denial of service (hypervisor and VM crash) by triggering a safety check (bsc#988676) - CVE-2016-5337: The megasas_ctrl_get_info function in hw/scsi/megasas.c in QEMU allowed local guest OS administrators to obtain sensitive host memory information via vectors related to reading device control information (bsc#983973) - CVE-2016-5338: The (1) esp_reg_read and (2) esp_reg_write functions in hw/scsi/esp.c in QEMU allowed local guest OS administrators to cause a denial of service (QEMU process crash) or execute arbitrary code on the QEMU host via vectors related to the information transfer buffer (bsc#983984) - CVE-2016-5238: The get_cmd function in hw/scsi/esp.c in QEMU allowed local guest OS administrators to cause a denial of service (out-of-bounds write and QEMU process crash) via vectors related to reading from the information transfer buffer in non-DMA mode (bsc#982960) - CVE-2016-4453: The vmsvga_fifo_run function in hw/display/vmware_vga.c in QEMU allowed local guest OS administrators to cause a denial of service (infinite loop and QEMU process crash) via a VGA command (bsc#982225) - CVE-2016-4454: The vmsvga_fifo_read_raw function in hw/display/vmware_vga.c in QEMU allowed local guest OS administrators to obtain sensitive host memory information or cause a denial of service (QEMU process crash) by changing FIFO registers and issuing a VGA command, which triggers an out-of-bounds read (bsc#982224) - CVE-2016-5126: Heap-based buffer overflow in the iscsi_aio_ioctl function in block/iscsi.c in QEMU allowed local guest OS users to cause a denial of service (QEMU process crash) or possibly execute arbitrary code via a crafted iSCSI asynchronous I/O ioctl call (bsc#982286) - CVE-2016-5105: The megasas_dcmd_cfg_read function in hw/scsi/megasas.c in QEMU, when built with MegaRAID SAS 8708EM2 Host Bus Adapter emulation support, used an uninitialized variable, which allowed local guest administrators to read host memory via vectors involving a MegaRAID Firmware Interface (MFI) command (bsc#982024) - CVE-2016-5106: The megasas_dcmd_set_properties function in hw/scsi/megasas.c in QEMU, when built with MegaRAID SAS 8708EM2 Host Bus Adapter emulation support, allowed local guest administrators to cause a denial of service (out-of-bounds write access) via vectors involving a MegaRAID Firmware Interface (MFI) command (bsc#982025) - CVE-2016-5107: The megasas_lookup_frame function in QEMU, when built with MegaRAID SAS 8708EM2 Host Bus Adapter emulation support, allowed local guest OS administrators to cause a denial of service (out-of-bounds read and crash) via unspecified vectors (bsc#982026) - CVE-2016-4963: The libxl device-handling allowed local guest OS users with access to the driver domain to cause a denial of service (management tool confusion) by manipulating information in the backend directories in xenstore (bsc#979670) - CVE-2016-4962: The libxl device-handling allowed local OS guest administrators to cause a denial of service (resource consumption or management facility confusion) or gain host OS privileges by manipulating information in guest controlled areas of xenstore (bsc#979620) - CVE-2016-4952: Out-of-bounds access issue in pvsci_ring_init_msg/data routines (bsc#981276) - CVE-2016-3710: The VGA module improperly performed bounds checking on banked access to video memory, which allowed local guest OS administrators to execute arbitrary code on the host by changing access modes after setting the bank register, aka the last seen 2020-06-05 modified 2016-10-12 plugin id 94000 published 2016-10-12 reporter This script is Copyright (C) 2016-2020 Tenable Network Security, Inc. source https://www.tenable.com/plugins/nessus/94000 title openSUSE Security Update : xen (openSUSE-2016-1170) (Bunker Buster) NASL family SuSE Local Security Checks NASL id SUSE_SU-2016-2473-1.NASL description This update for xen fixes several issues. These security issues were fixed : - CVE-2016-7092: The get_page_from_l3e function in arch/x86/mm.c in Xen allowed local 32-bit PV guest OS administrators to gain host OS privileges via vectors related to L3 recursive pagetables (bsc#995785). - CVE-2016-7093: Xen allowed local HVM guest OS administrators to overwrite hypervisor memory and consequently gain host OS privileges by leveraging mishandling of instruction pointer truncation during emulation (bsc#995789). - CVE-2016-7094: Buffer overflow in Xen allowed local x86 HVM guest OS administrators on guests running with shadow paging to cause a denial of service via a pagetable update (bsc#995792). - CVE-2016-6836: Information leakage in vmxnet3_complete_packet (bsc#994761). - CVE-2016-6888: Integer overflow in packet initialisation in VMXNET3 device driver. Aprivileged user inside guest c... (bsc#994772). - CVE-2016-6833: Use after free while writing (bsc#994775). - CVE-2016-6835: Buffer overflow in vmxnet_tx_pkt_parse_headers() in vmxnet3 deviceemulation. (bsc#994625). - CVE-2016-6834: An infinite loop during packet fragmentation (bsc#994421). - CVE-2016-6258: The PV pagetable code in arch/x86/mm.c in Xen allowed local 32-bit PV guest OS administrators to gain host OS privileges by leveraging fast-paths for updating pagetable entries (bsc#988675). - CVE-2016-6259: Xen did not implement Supervisor Mode Access Prevention (SMAP) whitelisting in 32-bit exception and event delivery, which allowed local 32-bit PV guest OS kernels to cause a denial of service (hypervisor and VM crash) by triggering a safety check (bsc#988676). The update package also includes non-security fixes. See advisory for details. Note that Tenable Network Security has extracted the preceding description block directly from the SUSE security advisory. Tenable has attempted to automatically clean and format it as much as possible without introducing additional issues. last seen 2020-06-01 modified 2020-06-02 plugin id 93935 published 2016-10-10 reporter This script is Copyright (C) 2016-2019 and is owned by Tenable, Inc. or an Affiliate thereof. source https://www.tenable.com/plugins/nessus/93935 title SUSE SLED12 / SLES12 Security Update : xen (SUSE-SU-2016:2473-1) (Bunker Buster)