CVE-2016-7237 : Détail

CVE-2016-7237

6.5
/
Moyen
A01-Broken Access Control
90.83%V3
Network
2016-11-10
05h16 +00:00
2018-10-12
17h57 +00:00
CVE.org
NVD
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Descriptions du CVE

Local Security Authority Subsystem Service (LSASS) in Microsoft Windows Vista SP2, Windows Server 2008 SP2 and R2 SP1, Windows 7 SP1, Windows 8.1, Windows Server 2012 Gold and R2, Windows RT 8.1, Windows 10 Gold, 1511, and 1607, and Windows Server 2016 allows remote authenticated users to cause a denial of service (system hang) via a crafted request, aka "Local Security Authority Subsystem Service Denial of Service Vulnerability."

Informations du CVE

Faiblesses connexes

CWE-ID Nom de la faiblesse Source
CWE-284 Improper Access Control
The product does not restrict or incorrectly restricts access to a resource from an unauthorized actor.

Métriques

Métriques Score Gravité CVSS Vecteur Source
V3.0 6.5 MEDIUM CVSS:3.0/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/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

A vulnerability exploitable with network access means the vulnerable component is bound to the network stack and the attacker's path is through OSI layer 3 (the network layer). Such a vulnerability is often termed 'remotely exploitable' and can be thought of as an attack being exploitable one or more network hops away (e.g. across layer 3 boundaries from 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 against the vulnerable component.

Privileges Required

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

Low

The attacker is authorized with (i.e. requires) privileges that provide basic user capabilities that could normally affect only settings and files owned by a user. Alternatively, an attacker with Low privileges may have the ability to cause an impact only to non-sensitive resources.

User Interaction

This metric captures the requirement for a 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

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.

None

There is no loss of confidentiality within the impacted component.

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.

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:L/Au:S/C:N/I:N/A:C [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 : 40744

Date de publication : 2016-11-08 23h00 +00:00
Auteur : laurent gaffie
EDB Vérifié : Yes

MS16-137: LSASS Remote Memory Corruption Advisory Title: LSASS SMB NTLM Exchange Remote Memory Corruption Version: 1.0 Issue type: Null Pointer Dereference Authentication: Pre-Authenticated Affected vendor: Microsoft Release date: 8/11/2016 Discovered by: Laurent Gaffié Advisory by: Laurent Gaffié Issue status: Patch available Affected versions: Windows: XP/Server 2003, Vista, 7, 2008R2, Server 2012R2, 10. ================================================= A vulnerability in Windows Local Security Authority Subsystem Service (LSASS) was found on Windows OS versions ranging from Windows XP through to Windows 10. This vulnerability allows an attacker to remotely crash the LSASS.EXE process of an affected workstation with no user interaction. Successful remote exploitation of this issue will result in a reboot of the target machine. Local privilege escalation should also be considered likely. Microsoft acknowledged the vulnerability and has published an advisory and a patch, resolving this issue. Technical details ----------------- This vulnerability affects both LSASS client and server and can be triggered remotely via SMBv1 and SMBv2, during the NTLM message 3 (Authenticate) message. Incoming NTLM messages via SMB are using ASN1 and DER encoding, the first ASN length field can be set to unsigned int by using 0x84. This allows an attacker to remotely allocate a huge chunk of memory, for a message never larger than 20000 chars. The secondary trigger is to set any string fields (User, Domain, session Key, MIC, etc) with a long string (80-140 chars), leading LSASS.exe to crash. eax=00000000 ebx=000e3e04 ecx=fffffff8 edx=fffffffc esi=000e3e00 edi=00000004 eip=7c84cca2 esp=00aaf9ac ebp=00aaf9d4 iopl=0 nv up ei pl nz ac po cy cs=001b ss=0023 ds=0023 es=0023 fs=003b gs=0000 efl=00010213 ntdll!RtlpWaitOnCriticalSection+0xdf: 7c84cca2 ff4014 inc dword ptr [eax+14h] ds:0023:00000014=???????? STACK_TEXT: 00aaf9d4 7c83cfd7 00000b3c 00000004 00000000 ntdll!RtlpWaitOnCriticalSection+0xdf 00aaf9f4 4ab82f4a 000e3e00 00aafbec 00000000 ntdll!RtlEnterCriticalSection+0xa8 <-- Is used with a null pointer 00aafa18 4ab82765 000e3de8 ffffffff 00000001 lsasrv!NegpBuildMechListFromCreds+0x25 <-- Uses a null creds. 00aafbfc 4abc8fbb 00000001 00aafe40 000e3de8 lsasrv!NegBuildRequestToken+0xd9 00aafc34 4abca13f 000e3de8 00120111 00000010 lsasrv!NegGenerateServerRequest+0x2a 00aafc98 4ab85edb 000e3de8 00000000 00aafe40 lsasrv!NegAcceptLsaModeContext+0x344 00aafd0c 4ab860c8 00d5f900 00d5f908 00aafe40 lsasrv!WLsaAcceptContext+0x139 00aafe84 4ab7ae7b 00d5f8d8 005ccaf0 00599048 lsasrv!LpcAcceptContext+0x13b 00aafe9c 4ab7ad7e 00d5f8d8 4ac22738 00d5a158 lsasrv!DispatchAPI+0x46 00aaff54 4ab7a7c9 00d5f8d8 00aaff9c 77e5baf1 lsasrv!LpcHandler+0x1fe 00aaff78 4ab8f448 00598ce8 00000000 00000000 lsasrv!SpmPoolThreadBase+0xb9 00aaffb8 77e6484f 0059ade8 00000000 00000000 lsasrv!LsapThreadBase+0x91 00aaffec 00000000 4ab8f3f1 0059ade8 00000000 kernel32!BaseThreadStart+0x34 dt ntdll!_RTL_CRITICAL_SECTION +0x000 DebugInfo : Ptr32 _RTL_CRITICAL_SECTION_DEBUG +0x004 LockCount : Int4B +0x008 RecursionCount : Int4B +0x00c OwningThread : Ptr32 Void +0x010 LockSemaphore : Ptr32 Void +0x014 SpinCount : Uint4B - LSASS NegpBuildMechListFromCreds sends a null pointer "creds" to NTDLL RtlEnterCriticalSection. - RtlEnterCriticalSection is used with a null pointer, which triggers the crash. Impact ------ Successful attempts will result in a remote system crash and possibly local privilege escalation. Affected products ----------------- Windows: - XP - Server 2003 - 7 - 8 - 2008 - 2012 - 10 Proof of concept ---------------- A proof of concept is available at the following URL: https://github.com/lgandx/PoC/tree/master/LSASS https://gitlab.com/exploit-database/exploitdb-bin-sploits/-/raw/main/bin-sploits/40744.zip This proof of concept is fully automated and includes non-vulnerable detection. Solution -------- Install the corresponding MS patch. More details: https://technet.microsoft.com/en-us/library/security/ms16-137.aspx Response timeline ----------------- * 17/09/2016 - Vendor notified, proof of concept sent. * 28/09/2016 - Issue confirmed by MSRC * 14/10/2016 - Vendor says he plan to release a patch in November, that is 1 month in advance of the scheduled 3 month. * 08/11/2016 - Vendor release MS16-137. * 08/11/2016 - This advisory released. References ---------- * https://twitter.com/PythonResponder * https://github.com/lgandx/Responder

Products Mentioned

Configuraton 0

Microsoft>>Windows_10 >> Version -

Microsoft>>Windows_10 >> Version 1511

Microsoft>>Windows_10 >> Version 1607

Microsoft>>Windows_7 >> Version *

Microsoft>>Windows_8.1 >> Version *

Microsoft>>Windows_rt_8.1 >> Version *

Microsoft>>Windows_server_2008 >> Version *

Microsoft>>Windows_server_2008 >> Version r2

Microsoft>>Windows_server_2012 >> Version -

Microsoft>>Windows_server_2012 >> Version r2

Microsoft>>Windows_server_2016 >> Version *

Microsoft>>Windows_vista >> Version *

Références

http://www.securitytracker.com/id/1037249
Tags : vdb-entry, x_refsource_SECTRACK
http://www.securityfocus.com/bid/94040
Tags : vdb-entry, x_refsource_BID
https://www.exploit-db.com/exploits/40744/
Tags : exploit, x_refsource_EXPLOIT-DB