CVE-2019-8613 : Détail

CVE-2019-8613

9.8
/
Critique
Memory Corruption
7.06%V3
Network
2019-12-18
16h33 +00:00
2019-12-18
16h33 +00:00
CVE.org
NVD
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Descriptions du CVE

A use after free issue was addressed with improved memory management. This issue is fixed in iOS 12.3, tvOS 12.3, watchOS 5.2.1. A remote attacker may be able to cause arbitrary code execution.

Informations du CVE

Faiblesses connexes

CWE-ID Nom de la faiblesse Source
CWE-416 Use After Free
The product reuses or references memory after it has been freed. At some point afterward, the memory may be allocated again and saved in another pointer, while the original pointer references a location somewhere within the new allocation. Any operations using the original pointer are no longer valid because the memory "belongs" to the code that operates on the new pointer.

Métriques

Métriques Score Gravité CVSS Vecteur Source
V3.1 9.8 CRITICAL CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Base: Exploitabilty Metrics

The Exploitability metrics reflect the characteristics of the thing that is vulnerable, which we refer to formally as the vulnerable component.

Attack Vector

This metric reflects the context by which vulnerability exploitation is possible.

Network

The vulnerable component is bound to the network stack and the set of possible attackers extends beyond the other options listed below, up to and including the entire Internet. Such a vulnerability is often termed “remotely exploitable” and can be thought of as an attack being exploitable at the protocol level one or more network hops away (e.g., across one or more routers).

Attack Complexity

This metric describes the conditions beyond the attacker’s control that must exist in order to exploit the vulnerability.

Low

Specialized access conditions or extenuating circumstances do not exist. An attacker can expect repeatable success when attacking the vulnerable component.

Privileges Required

This metric describes the level of privileges an attacker must possess before successfully exploiting the vulnerability.

None

The attacker is unauthorized prior to attack, and therefore does not require any access to settings or files of the vulnerable system to carry out an attack.

User Interaction

This metric captures the requirement for a human user, other than the attacker, to participate in the successful compromise of the vulnerable component.

None

The vulnerable system can be exploited without interaction from any user.

Base: Scope Metrics

The Scope metric captures whether a vulnerability in one vulnerable component impacts resources in components beyond its security scope.

Scope

Formally, a security authority is a mechanism (e.g., an application, an operating system, firmware, a sandbox environment) that defines and enforces access control in terms of how certain subjects/actors (e.g., human users, processes) can access certain restricted objects/resources (e.g., files, CPU, memory) in a controlled manner. All the subjects and objects under the jurisdiction of a single security authority are considered to be under one security scope. If a vulnerability in a vulnerable component can affect a component which is in a different security scope than the vulnerable component, a Scope change occurs. Intuitively, whenever the impact of a vulnerability breaches a security/trust boundary and impacts components outside the security scope in which vulnerable component resides, a Scope change occurs.

Unchanged

An exploited vulnerability can only affect resources managed by the same security authority. In this case, the vulnerable component and the impacted component are either the same, or both are managed by the same security authority.

Base: Impact Metrics

The Impact metrics capture the effects of a successfully exploited vulnerability on the component that suffers the worst outcome that is most directly and predictably associated with the attack. Analysts should constrain impacts to a reasonable, final outcome which they are confident an attacker is able to achieve.

Confidentiality Impact

This metric measures the impact to the confidentiality of the information resources managed by a software component due to a successfully exploited vulnerability.

High

There is a total loss of confidentiality, resulting in all resources within the impacted component being divulged to the attacker. Alternatively, access to only some restricted information is obtained, but the disclosed information presents a direct, serious impact. For example, an attacker steals the administrator's password, or private encryption keys of a web server.

Integrity Impact

This metric measures the impact to integrity of a successfully exploited vulnerability. Integrity refers to the trustworthiness and veracity of information.

High

There is a total loss of integrity, or a complete loss of protection. For example, the attacker is able to modify any/all files protected by the impacted component. Alternatively, only some files can be modified, but malicious modification would present a direct, serious consequence to the impacted component.

Availability Impact

This metric measures the impact to the availability of the impacted component resulting from a successfully exploited vulnerability.

High

There is a total loss of availability, resulting in the attacker being able to fully deny access to resources in the impacted component; this loss is either sustained (while the attacker continues to deliver the attack) or persistent (the condition persists even after the attack has completed). Alternatively, the attacker has the ability to deny some availability, but the loss of availability presents a direct, serious consequence to the impacted component (e.g., the attacker cannot disrupt existing connections, but can prevent new connections; the attacker can repeatedly exploit a vulnerability that, in each instance of a successful attack, leaks a only small amount of memory, but after repeated exploitation causes a service to become completely unavailable).

Temporal Metrics

The Temporal metrics measure the current state of exploit techniques or code availability, the existence of any patches or workarounds, or the confidence in the description of a vulnerability.

Environmental Metrics

These metrics enable the analyst to customize the CVSS score depending on the importance of the affected IT asset to a user’s organization, measured in terms of Confidentiality, Integrity, and Availability.

 [email protected]
V2 7.5 AV:N/AC:L/Au:N/C:P/I:P/A:P [email protected]

EPSS

EPSS est un modèle de notation qui prédit la probabilité qu'une vulnérabilité soit exploitée.

Score EPSS

Le modèle EPSS produit un score de probabilité compris entre 0 et 1 (0 et 100 %). Plus la note est élevée, plus la probabilité qu'une vulnérabilité soit exploitée est grande.

Percentile EPSS

Le percentile est utilisé pour classer les CVE en fonction de leur score EPSS. Par exemple, une CVE dans le 95e percentile selon son score EPSS est plus susceptible d'être exploitée que 95 % des autres CVE. Ainsi, le percentile sert à comparer le score EPSS d'une CVE par rapport à d'autres CVE.
EPSS First.org

Informations sur l'Exploit

Exploit Database EDB-ID : 46913

Date de publication : 2019-05-22 22h00 +00:00
Auteur : Google Security Research
EDB Vérifié : Yes

Visual Voicemail (VVM) is a feature of mobile devices that allows voicemail to be read in an email-like format. Carriers set up a Visual Voicemail server that supports IMAP, and the device queries this server for new email. Visual Voicemail is configured over SMS, and carriers inform devices of the location of the IMAP server by sending a specially formatted SMS message containing the URL of the IMAP server. SMS messages are determined to be VVM-related based on their PID field as well as their contents. Both of these fields can be set by a device sending SMS messages, so any device can send a message that causes Visual Voicemail to query an IMAP server specified in the message. This means that an attacker can force a device to query an IMAP server they control without the user interacting with the device in any way. There is an object lifetime issue in the iPhone IMAP client that can be accessed in this way. It happens when a NAMESPACE command response contains a namespace that cannot be parsed correctly. It leads to the mailbox separator being freed, but not replaced with a valid object. This leads to a selector being called on an object that is not valid. To reproduce this issue: 1) Run testcrash.py on a remotely accessible server. To run on port 993, this will need to be on a server that has a domain name, and a certificate that verifies correctly. Replace the "YOUR KEY HERE" fields in testcrash.py with the location of the cert files. On some carriers, it is possible to use port 143 without SSL instead. 2) Send the attached SMS messages to the device, first statepdu.txt and then mboxupdatepdu.txt. Replace the destination number and server location in the messages with the location of your target device and server before sending. 3) The device will connect to the server, and then crash Note that this attack depends somewhat on the carrier the device is on. I tested this issue on an AT&T SIM. I was not able to reproduce this issue on a T-Mobile SIM, because their network does not allow VVM connections to outside servers. It might be possible to bypass this by hosting the server on a peer device on the network, but I didn't try this. The PID used for VVM SMS messages also varies based on carrier. I've attached a crash log for this issue. I've also attached decoded.txt, which describes the contents of the SMS pdus, and NAMESPACE.zip, which is a non-minimized PoC that leaders to a wider variety of crashes. When retrieving a message, the VVM client calls [IMAPAccount _updateSeparatorAndNamespaceWithConnection:] to get the server separator and namespace prefix. This method first retrieves the server separator by calling [MFIMAPConnection separatorChar] which causes the LIST command to be sent to the server, and returns the separator. The method also stores the separator as a member of the connection object, which gives the separator its sole reference. [IMAPAccount _updateSeparatorAndNamespaceWithConnection:] then calls [MFIMAPConnection serverPathPrefix] to get the prefix, which in turn calls [MFIMAPConnection _doNamespaceCommand] to perform the NAMESPACE command over the network. If this command fails for any reason (for example, malformed response, LOGOUT command, etc.), it will call [MFIMAPConnection disconnectAndNotifyDelegate:], which removes the separator from the connection object, removing its only reference. The rest of [IMAPAccount _updateSeparatorAndNamespaceWithConnection:] will then use a separator object that has been freed. This issue was resolved by adding a lock to [IMAPAccount _updateSeparatorAndNamespaceWithConnection:] and [MFIMAPConnection disconnectAndNotifyDelegate:] so that they cannot run at the same time for the same connection. This issue was fixed on Tuesday, May 14 Proof of Concept: https://gitlab.com/exploit-database/exploitdb-bin-sploits/-/raw/main/bin-sploits/46913.zip

Products Mentioned

Configuraton 0

Apple>>Iphone_os >> Version To (excluding) 12.3

Apple>>Tvos >> Version To (excluding) 12.3

Apple>>Watchos >> Version To (excluding) 5.2.1

Références