English
Français
Light
Dark
System

CVEFind - Alertes CVE

Restez informé en continue
Créer un compte Ouvrez un compte Simple et Gratuit Se connecter Gérez vos alertes

CVE-2019-0573 : Détail

CVE-2019-0573

7.8
/
HIGH
Authorization problems
A01-Broken Access Control
0.22%V3
Local
2019-01-08 20:00 +00:00
2019-01-15 09:57 +00:00
CVE.org
NVD

Alerte pour un CVE

Restez informé de toutes modifications pour un CVE spécifique.
Gestion des alertes

Descriptions

An elevation of privilege vulnerability exists when the Windows Data Sharing Service improperly handles file operations, aka "Windows Data Sharing Service Elevation of Privilege Vulnerability." This affects Windows Server 2016, Windows 10, Windows Server 2019, Windows 10 Servers. This CVE ID is unique from CVE-2019-0571, CVE-2019-0572, CVE-2019-0574.

Informations

Faiblesses connexes

CWE-ID Nom de la faiblesse Source
CWE-862 Missing Authorization
The product does not perform an authorization check when an actor attempts to access a resource or perform an action.

Metrics

Metric Score Sévérité 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.

EPSS Score

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.

EPSS Percentile

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 : 46158

Date de publication : 2019-01-13 23:00 +00:00
Auteur : Google Security Research
EDB Vérifié : Yes

Windows: DSSVC DSOpenSharedFile Arbitrary File Delete EoP Platform: Windows 10 1803 and 1809. Class: Elevation of Privilege Security Boundary (per Windows Security Service Criteria): User boundary NOTE: This is one of multiple issues I’m reporting in the same service. While I’ve tried to ensure all the bugs are effectively orthogonal from each other it’s possible that fixes for one thing might affect others. I’ve also not reported every possible problem with the service as at some point I had to stop. I’ve not determined if any of these issues could be abusable from a sandbox, most of the issues almost certainly can’t be due to the requirements for arbitrary file symlinks but it’s not impossible. Summary: The Data Sharing Service DSOpenSharedFile method takes a flag to delete a shared file on close which can be abused to delete an arbitrary file. Description: The DSOpenSharedFile method takes a flag parameter where the file handle can be opened overlapped or for delete on close. The delete on close flag will set the flag FILE_FLAG_DELETE_ON_CLOSE when opening the file with CreateFile. This code runs as SYSTEM so will open any file that that user has access to. However there’s a couple of issues with this: 1) The code doesn’t check that the file was shared writable, which means it’s possible to trivially specify a file to DSCreateSharedFileToken you want to delete and specify read only permissions. Then call DSOpenSharedFile with the delete on close flag, as the flag automatically adds the DELETE permission to the file open this will succeed even with the read-only mode set. 2) The DSOpenSharedFile relies on calling DSUtils::VerifyPathFromHandle prevent returning a handle which was redirected due to something like a symlink or directory junction. However by the time the code reaches the verification it’s already too late and the file will delete on close regardless of what the service now does. While this bug relies on the same behavior as I reported for the arbitrary hardlink open issue (namely not impersonating the user when calling CreateFile) I think it should be treated separately, unless of course you decide to do the impersonation as a fix. At a minimum you should be checking that the file was shared writable in case 1, and perhaps you should open the file for DELETE in case 2, verify the path and only then delete the file by handle (using the native APIs). Proof of Concept: I’ve provided a PoC as a C# project. It will delete an arbitrary file that the user can read by abusing case 1 above. 1) Compile the C# project. It’ll need to pull NtApiDotNet from NuGet to build. 2) Execute the PoC passing the path to a file the user can’t delete on the command line (but can be deleted by SYSTEM). Expected Result: The call to DSOpenSharedFile fails and the file isn’t deleted. Observed Result: The file specified is deleted. Proof of Concept: https://gitlab.com/exploit-database/exploitdb-bin-sploits/-/raw/main/bin-sploits/46158.zip

Products Mentioned

Configuraton 0

Microsoft>>Windows_10 >> Version -

Microsoft>>Windows_10 >> Version 1607

Microsoft>>Windows_10 >> Version 1703

Microsoft>>Windows_10 >> Version 1709

Microsoft>>Windows_10 >> Version 1803

Microsoft>>Windows_10 >> Version 1809

Microsoft>>Windows_server_2016 >> Version -

Microsoft>>Windows_server_2016 >> Version 1709

Microsoft>>Windows_server_2016 >> Version 1803

Microsoft>>Windows_server_2019 >> Version -

References

http://www.securityfocus.com/bid/106430
Tags : vdb-entry, x_refsource_BID
https://www.exploit-db.com/exploits/46158/
Tags : exploit, x_refsource_EXPLOIT-DB

Plus d'informations
Cliquez sur le bouton à gauche (OFF), pour autoriser l'inscription de cookie améliorant les fonctionnalités du site. Cliquez sur le bouton à gauche (Tout accepter), pour ne plus autoriser l'inscription de cookie améliorant les fonctionnalités du site.