CVE-2017-2509 : Détail

CVE-2017-2509

5.5
/
Moyen
1.65%V4
Local
2017-05-22
02h54 +00:00
2017-08-12
07h57 +00:00
CVE.org
NVD
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Descriptions du CVE

An issue was discovered in certain Apple products. macOS before 10.12.5 is affected. The issue involves the "Kernel" component. It allows attackers to bypass intended memory-read restrictions via a crafted app.

Informations du CVE

Faiblesses connexes

CWE-ID Nom de la faiblesse Source
CWE Other No informations.

Métriques

Métriques Score Gravité CVSS Vecteur Source
V3.0 5.5 MEDIUM CVSS:3.0/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N

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.

Local

A vulnerability exploitable with Local access means that the vulnerable component is not bound to the network stack, and the attacker's path is via read/write/execute capabilities. In some cases, the attacker may be logged in locally in order to exploit the vulnerability, otherwise, she may rely on User Interaction to execute a malicious file.

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 against 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 to carry out an attack.

User Interaction

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

Required

Successful exploitation of this vulnerability requires a user to take some action before the vulnerability can be exploited. For example, a successful exploit may only be possible during the installation of an application by a system administrator.

Base: Scope Metrics

An important property captured by CVSS v3.0 is the ability for a vulnerability in one software component to impact resources beyond its means, or privileges.

Scope

Formally, Scope refers to the collection of privileges defined by a computing authority (e.g. an application, an operating system, or a sandbox environment) when granting access to computing resources (e.g. files, CPU, memory, etc). These privileges are assigned based on some method of identification and authorization. In some cases, the authorization may be simple or loosely controlled based upon predefined rules or standards. For example, in the case of Ethernet traffic sent to a network switch, the switch accepts traffic that arrives on its ports and is an authority that controls the traffic flow to other switch ports.

Unchanged

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

Base: Impact Metrics

The Impact metrics refer to the properties of the impacted component.

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 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.

None

There is no loss of integrity within the impacted component.

Availability Impact

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

None

There is no impact to availability within the impacted component.

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 that one has in the description of a vulnerability.

Environmental Metrics

 nvd@nist.gov
V2 4.3 AV:N/AC:M/Au:N/C:P/I:N/A:N nvd@nist.gov

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 : 42046

Date de publication : 2017-05-21 22h00 +00:00
Auteur : Google Security Research
EDB Vérifié : Yes

Source: https://bugs.chromium.org/p/project-zero/issues/detail?id=1149 The XNU kernel, when compiled for a x86-64 CPU, can run 32-bit x86 binaries in compatibility mode. 32-bit binaries use partly separate syscall entry and exit paths. To return to userspace, unix_syscall() in bsd/dev/i386/systemcalls.c calls thread_exception_return() (in osfmk/x86_64/locore.s), which in turn calls return_from_trap, which is implemented in osfmk/x86_64/idt64.s. return_from_trap() normally branches into return_to_user relatively quickly, which then, depending on the stack segment selector, branches into either L_64bit_return or L_32bit_return. While the L_64bit_return path restores all userspace registers, the L_32bit_return path only restores the registers that are accessible in compatibility mode; the registers r8 to r15 are not restored. This is bad because, although switching to compatibility mode makes it impossible to directly access r8..r15, the register contents are preserved, and switching back to 64-bit mode makes the 64-bit registers accessible again. Since the GDT always contains user code segments for both compatibility mode and 64-bit mode, an unprivileged 32-bit process can leak kernel register contents as follows: - make a normal 32-bit syscall - switch to 64-bit mode (e.g. by loading the 64-bit user code segment using iret) - store the contents of r8..r15 - switch back to compatibility mode (e.g. by loading the 32-bit user code segment using iret) The attached PoC demonstrates the issue by dumping the contents of r8..r15. Usage: $ ./leakregs r8 = 0xffffff801d3872a8 r9 = 0xffffff8112abbec8 r10 = 0xffffff801f962240 r11 = 0xffffff8031d52bb0 r12 = 0x12 r13 = 0xffffff80094018f0 r14 = 0xffffff801cb59ea0 r15 = 0xffffff801cb59ea0 It seems like these are various types of kernel pointers, including kernel text pointers. If you want to compile the PoC yourself, you'll have to adjust the path to nasm in compile.sh, then run ./compile.sh. This bug was verified using the following kernel version: 15.6.0 Darwin Kernel Version 15.6.0: Mon Jan 9 23:07:29 PST 2017; root:xnu-3248.60.11.2.1~1/RELEASE_X86_64 x86_64 Proof of Concept: https://gitlab.com/exploit-database/exploitdb-bin-sploits/-/raw/main/bin-sploits/42046.zip

Products Mentioned

Configuraton 0

Apple>>Mac_os_x >> Version To (including) 10.12.4

Références

https://www.exploit-db.com/exploits/42046/
Tags : exploit, x_refsource_EXPLOIT-DB
http://www.securitytracker.com/id/1038484
Tags : vdb-entry, x_refsource_SECTRACK
https://support.apple.com/HT207797
Tags : x_refsource_CONFIRM