Vulnerabilities > CVE-2017-7116 - Information Exposure vulnerability in Apple Iphone OS
Attack vector
NETWORK Attack complexity
LOW Privileges required
NONE Confidentiality impact
HIGH Integrity impact
NONE Availability impact
NONE Summary
An issue was discovered in certain Apple products. iOS before 11 is affected. tvOS before 11 is affected. watchOS before 4 is affected. The issue involves the "Wi-Fi" component. It might allow remote attackers to read data from kernel memory locations via crafted Wi-Fi traffic.
Vulnerable Configurations
Common Weakness Enumeration (CWE)
Common Attack Pattern Enumeration and Classification (CAPEC)
- Subverting Environment Variable Values The attacker directly or indirectly modifies environment variables used by or controlling the target software. The attacker's goal is to cause the target software to deviate from its expected operation in a manner that benefits the attacker.
- Footprinting An attacker engages in probing and exploration activity to identify constituents and properties of the target. Footprinting is a general term to describe a variety of information gathering techniques, often used by attackers in preparation for some attack. It consists of using tools to learn as much as possible about the composition, configuration, and security mechanisms of the targeted application, system or network. Information that might be collected during a footprinting effort could include open ports, applications and their versions, network topology, and similar information. While footprinting is not intended to be damaging (although certain activities, such as network scans, can sometimes cause disruptions to vulnerable applications inadvertently) it may often pave the way for more damaging attacks.
- Exploiting Trust in Client (aka Make the Client Invisible) An attack of this type exploits a programs' vulnerabilities in client/server communication channel authentication and data integrity. It leverages the implicit trust a server places in the client, or more importantly, that which the server believes is the client. An attacker executes this type of attack by placing themselves in the communication channel between client and server such that communication directly to the server is possible where the server believes it is communicating only with a valid client. There are numerous variations of this type of attack.
- Browser Fingerprinting An attacker carefully crafts small snippets of Java Script to efficiently detect the type of browser the potential victim is using. Many web-based attacks need prior knowledge of the web browser including the version of browser to ensure successful exploitation of a vulnerability. Having this knowledge allows an attacker to target the victim with attacks that specifically exploit known or zero day weaknesses in the type and version of the browser used by the victim. Automating this process via Java Script as a part of the same delivery system used to exploit the browser is considered more efficient as the attacker can supply a browser fingerprinting method and integrate it with exploit code, all contained in Java Script and in response to the same web page request by the browser.
- Session Credential Falsification through Prediction This attack targets predictable session ID in order to gain privileges. The attacker can predict the session ID used during a transaction to perform spoofing and session hijacking.
Nessus
| NASL family | Misc. |
| NASL id | APPLETV_11.NASL |
| description | According to its banner, the version of Apple TV on the remote device is prior to 11. It is, therefore, affected by multiple vulnerabilities as described in the HT208113 security advisory. Note that only 4th generation models are affected by these vulnerabilities. |
| last seen | 2020-06-01 |
| modified | 2020-06-02 |
| plugin id | 103419 |
| published | 2017-09-22 |
| reporter | This script is Copyright (C) 2017-2019 and is owned by Tenable, Inc. or an Affiliate thereof. |
| source | https://www.tenable.com/plugins/nessus/103419 |
| title | Apple TV < 11 Multiple Vulnerabilities |
| code | |
Seebug
| bulletinFamily | exploit |
| description | Broadcom produces Wi-Fi HardMAC SoCs which are used to handle the PHY and MAC layer processing. These chips are present in both mobile devices and Wi-Fi routers, and are capable of handling many Wi-Fi related events without delegating to the host OS. On iOS, the "AppleBCMWLANBusInterfacePCIe" driver is used in order to handle the PCIe interface and low-level communication protocols with the Wi-Fi SoC (also referred to as "dongle"). Similarly, the "AppleBCMWLANCore" driver handles the high-level protocols and the Wi-Fi configuration. When the dongle wishes to notify the host OS of an event, it does so by encoding a special "packet" and transmitting it to the host. These packets have an ether type of 0x886C, and do not contain actual packet data, but rather encapsulate information about events which must be handled by the driver. One of the supported event packets is the WLC_E_COUNTRY_CODE_CHANGED message, which notifies that host that the country code has been modified. On iOS, these events are handled by the "handleCountryCodeChangedEvent" function in the "AppleBCMWLANCore" driver. Each packet of this type starts with the common event message header (which is 48 bytes long), followed by the 3-character country code, delimited by a NUL. Here is a snippet of "handleCountryCodeChangedEvent"'s high-level logic: ``` int64_t handleCountryCodeChangedEvent(void* this, uint8_t* event_packet) { char* country_code = (char*)this + 3244; char* alt_country_code = (char*)this + 3248; strncpy(country_code, event_packet + 48, 3); country_code[3] = '\0'; if ( strncmp(country_code, "XZ", strlen("XZ")) && strncmp(alt_country_code, country_code 4)) { strncpy(alt_country_code, country_code, 3); alt_country_code[3] = '\0'; updateChannelSpecsAsync(this); } ... } int64_t updateChannelSpecsAsync(void* this) { char request_buffer[0x1C2]; bzero(request_buffer, 0x1C2); char* country_code = (char*)this + 3244; strlcpy(request_buffer, country_code, 4); return issueCommand(..., request_buffer, ...); //Getting the "chanspecs" IO-Var ... } ``` As can be seen above, the function fails to verify that the length of the event message is sufficiently long (that is, larger than just the message header itself). As a result, an attacker controlling the dongle can send a WLC_E_COUNTRY_CODE_CHANGED event packet with no body payload. Doing so will cause the 3 bytes of the country code to be copied OOB (from event_packet + 48). As long as these bytes are not "XZ" or the previously stored country code ("alt_country_code"), "updateChannelSpecsAsync" will be called, causing the OOB data to be sent back to the dongle in the WLC_GET_VAR ioctl - thus leaking the bytes back to the dongle. |
| id | SSV:96628 |
| last seen | 2017-11-19 |
| modified | 2017-10-10 |
| published | 2017-10-10 |
| reporter | Root |
| title | Apple: Information Leak when handling WLC_E_COUNTRY_CODE_CHANGED event packets(CVE-2017-7116) |
References
- http://www.securityfocus.com/bid/100927
- http://www.securityfocus.com/bid/100927
- http://www.securitytracker.com/id/1039385
- http://www.securitytracker.com/id/1039385
- https://bugs.chromium.org/p/project-zero/issues/detail?id=1318
- https://bugs.chromium.org/p/project-zero/issues/detail?id=1318
- https://support.apple.com/HT208112
- https://support.apple.com/HT208112
- https://support.apple.com/HT208113
- https://support.apple.com/HT208113
- https://support.apple.com/HT208115
- https://support.apple.com/HT208115