Vulnerabilities > CVE-2016-1751 - Permissions, Privileges, and Access Controls vulnerability in Apple Iphone OS and Watchos
Attack vector
LOCAL Attack complexity
LOW Privileges required
NONE Confidentiality impact
HIGH Integrity impact
HIGH Availability impact
HIGH Summary
The kernel in Apple iOS before 9.3, tvOS before 9.2, and watchOS before 2.2 does not properly restrict the execute permission, which allows attackers to bypass a code-signing protection mechanism via a crafted app.
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 | Misc. |
| NASL id | APPLETV_9_2.NASL |
| description | According to its banner, the remote Apple TV device is a version prior to 9.2. It is, therefore, affected by the following vulnerabilities : - An XML external entity (XXE) expansion flaw exists in libxml2 due to the XML parser accepting entities from untrusted sources. An unauthenticated, remote attacker can exploit this, via crafted XML data, to cause a denial of service through resource exhaustion. (CVE-2015-1819) - An XML external entity (XXE) injection flaw exists in libxml2 in file parser.c due to the XML parser accepting entities from untrusted sources. An unauthenticated, remote attacker can exploit this, via crafted XML data, to cause a denial of service or to disclose sensitive information. (CVE-2015-5312) - A heap buffer overflow condition exists in libxml2 in the xmlGROW() function within file parser.c while handling XML data. An unauthenticated, remote attacker can exploit this to disclose sensitive information. (CVE-2015-7499) - An out-of-bounds heap read error exists in libxml2 in the xmlParseMisc() function within file parser.c while handling entity boundaries. An unauthenticated, remote attacker can exploit this to cause a denial of service. (CVE-2015-7500) - An out-of-bounds read error exists in libxml2 in the xmlParseConditionalSections() function within file parser.c due to a failure to properly skip intermediary entities when it stops parsing invalid input. An unauthenticated, remote attacker can exploit this, via crafted XML data, to cause a denial of service. (CVE-2015-7942) - A flaw exists in libxml2 in the xz_decomp() function within file xzlib.c due to a failure to properly detect compression errors when handling compressed XML content. An unauthenticated, remote attacker can exploit this, via crafted XML data, to cause an infinite loop, resulting in a denial of service. (CVE-2015-8035) - A out-of-bounds read error exists in libxml2 in the xmlSAX2TextNode() function within file SAX2.c due to improper sanitization of input data. An unauthenticated, remote attacker can exploit this, via crafted XML data, to cause a denial of service or to disclose sensitive information. (CVE-2015-8242) - A use-after-free error exists in Nghttp2 within file lib/nghttp2_session.c when handling idle streams. An unauthenticated, remote attacker can exploit this to deference already freed memory, allowing the execution of arbitrary code. (CVE-2015-8659) - An overflow condition exists in the Broadcom Wi-Fi driver due to improper validation of data while handling SSID or WPS_ID_DEVICE_NAME values. An unauthenticated, adjacent attacker can exploit this, via a crafted wireless control message packet, to cause a denial of service or to execute arbitrary code. (CVE-2016-0801) - An overflow condition exists in the Broadcom Wi-Fi driver due to improper validation of user-supplied input when handling the packet length of event messages. An unauthenticated, adjacent attacker can exploit this, via a crafted wireless control message packet, to cause a denial of service or to execute arbitrary code. (CVE-2016-0802) - A flaw exists in FontParser due to improper validation of user-supplied input when handling encoded fonts that contain invalid characters. An unauthenticated, remote attacker can exploit this, via a crafted PDF document, to corrupt memory, resulting in a denial of service or the execution arbitrary code. (CVE-2016-1740) - A flaw exists in IOHIDFamily due to improper validation of user-supplied input. An unauthenticated, remote attacker can exploit this, via a crafted application, to gain access to kernel memory layout information. (CVE-2016-1748) - A use-after-free error exists in the kernel that allows an unauthenticated, remote attacker to execute arbitrary code via a crafted application. (CVE-2016-1750) - A flaw exists in the kernel due to a failure to properly restrict execution permissions. An unauthenticated, remote attacker can exploit this, via a crafted application, to bypass code-signing protection mechanisms. (CVE-2016-1751) - An unspecified flaw exists in the kernel that allows a local attacker to cause a denial of service via a crafted application. (CVE-2016-1752) - An integer overflow condition exists in the kernel due to improper validation of user-supplied input. An unauthenticated, remote attacker can exploit this, via a crafted application, to gain elevated privileges. (CVE-2016-1753) - A memory corruption issue exists in the kernel due to improper validation of user-supplied input. An unauthenticated, remote attacker can exploit this, by convincing a user to install a malicious application, to cause a denial of service or execute arbitrary code. CVE-2016-1754) - A use-after-free error exists in the AppleKeyStore user client when handling multiple threads, which is triggered when one thread closes the user client while another attempts to call an external method. An unauthenticated, remote attacker can exploit this, by convincing a user to install a malicious application, to execute arbitrary code with elevated privileges. (CVE-2016-1755) - A flaw exists in libxml2 due to improper validation of user-supplied input while handling XML content. An unauthenticated, remote attacker can exploit this, via a crafted XML document, to cause a denial of service or to execute arbitrary code. (CVE-2016-1762) - An out-of-bounds write error exists in TrueTypeScaler due to improper validation of user-supplied input while handling bdat tables in TTF fonts. An unauthenticated, remote attacker can exploit this, via a crafted TTF font, to cause a denial or service or to execute arbitrary code. (CVE-2016-1775) - A flaw exists in WebKit due to improper validation of user-supplied input. An unauthenticated, remote attacker can exploit this, via a crafted website, to cause a denial of service or execute arbitrary code. (CVE-2016-1783) - An unspecified flaw exists in the History implementation of WebKit that allows an unauthenticated, remote attacker to cause a denial of service via a crafted website. (CVE-2016-1784) - A heap buffer overflow condition exists in Mozilla Network Security Services due to improper validation of user-supplied input while parsing ASN.1 structures. An unauthenticated, remote attacker can exploit this, via crafted ASN.1 data in an X.509 certificate, to cause a denial of service or execute arbitrary code. (CVE-2016-1950) Note that only 4th generation models are affected by these vulnerabilities, and this plugin only checks these models. |
| last seen | 2020-06-01 |
| modified | 2020-06-02 |
| plugin id | 90309 |
| published | 2016-04-01 |
| 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/90309 |
| title | Apple TV < 9.2 Multiple Vulnerabilities |
| code | |
References
- https://support.apple.com/HT206166
- http://lists.apple.com/archives/security-announce/2016/Mar/msg00002.html
- https://support.apple.com/HT206169
- http://lists.apple.com/archives/security-announce/2016/Mar/msg00000.html
- https://support.apple.com/HT206168
- http://lists.apple.com/archives/security-announce/2016/Mar/msg00001.html
- http://www.securitytracker.com/id/1035353