VDB-92242 · CVE-2016-5720 · BID 95859

Microsoft Skype Installer cryptui.dll access control

CVSS Meta Temp Score
CVSS is a standardized scoring system to determine possibilities of attacks. The Temp Score considers temporal factors like disclosure, exploit and countermeasures. The unique Meta Score calculates the average score of different sources to provide a normalized scoring system.
Current Exploit Price (≈)
Our analysts are monitoring exploit markets and are in contact with vulnerability brokers. The range indicates the observed or calculated exploit price to be seen on exploit markets. A good indicator to understand the monetary effort required for and the popularity of an attack.
CTI Interest Score
Our Cyber Threat Intelligence team is monitoring different web sites, mailing lists, exploit markets and social media networks. The CTI Interest Score identifies the interest of attackers and the security community for this specific vulnerability in real-time. A high score indicates an elevated risk to be targeted for this vulnerability.
7.6$0-$5k0.00

A vulnerability classified as critical was found in Microsoft Skype (Unified Communication Software) (the affected version unknown). This vulnerability affects an unknown part in the library msi.dll/dpapi.dll/cryptui.dll of the component Installer. The manipulation with an unknown input leads to a access control vulnerability. The CWE definition for the vulnerability is CWE-264. As an impact it is known to affect confidentiality, integrity, and availability.

The weakness was disclosed 09/27/2016 as not defined mailinglist post (Full-Disclosure). The advisory is available at seclists.org. The vendor was not involved in the coordination of the public release. This vulnerability was named CVE-2016-5720 since 06/16/2016. The exploitation appears to be easy. Local access is required to approach this attack. A single authentication is necessary for exploitation. Technical details and also a public exploit are known. This vulnerability is assigned to T1068 by the MITRE ATT&CK project.

A public exploit has been developed in Binary and been published immediately after the advisory. It is possible to download the exploit at mega.nz. It is declared as proof-of-concept. As 0-day the estimated underground price was around $5k-$25k. The code used by the exploit is:

1. Download this dll https://mega.nz/#!b4ViSLJL!Pv99pN2d_WxsUHGPH0Ej3onwVeSdh41mpyKfQJfAq8E
2. Copy msi.dll to Downloads directory
3. download skype installer
4. execute the downloaded installer from your "Downloads" directory; Observed behavior: message box “hyhy”

There is no information about possible countermeasures known. It may be suggested to replace the affected object with an alternative product.

Productinfo

Type

Vendor

Name

License

  • free

CPE 2.3info

CPE 2.2info

CVSSv3info

VulDB Meta Base Score: 7.8
VulDB Meta Temp Score: 7.6

VulDB Base Score: 7.8
VulDB Temp Score: 7.4
VulDB Vector: 🔍
VulDB Reliability: 🔍

NVD Base Score: 7.8
NVD Vector: 🔍

CVSSv2info

AVACAuCIA
💳💳💳💳💳💳
💳💳💳💳💳💳
💳💳💳💳💳💳
VectorComplexityAuthenticationConfidentialityIntegrityAvailability
unlockunlockunlockunlockunlockunlock
unlockunlockunlockunlockunlockunlock
unlockunlockunlockunlockunlockunlock

VulDB Base Score: 🔍
VulDB Temp Score: 🔍
VulDB Reliability: 🔍

NVD Base Score: 🔍

Exploitinginfo

Class: Access control
CWE: CWE-264
ATT&CK: T1068

Local: Yes
Remote: No

Availability: 🔍
Access: Public
Status: Proof-of-Concept
Programming Language: 🔍
Download: 🔍

EPSS Score: 🔍
EPSS Percentile: 🔍

Price Prediction: 🔍
Current Price Estimation: 🔍

0-Dayunlockunlockunlockunlock
Todayunlockunlockunlockunlock

OpenVAS ID: 804587
OpenVAS Name: Microsoft Skype DLL Hijacking Vulnerability
OpenVAS File: 🔍
OpenVAS Family: 🔍

Threat Intelligenceinfo

Interest: 🔍
Active Actors: 🔍
Active APT Groups: 🔍

Countermeasuresinfo

Recommended: no mitigation known
Status: 🔍

0-Day Time: 🔍
Exploit Delay Time: 🔍

Timelineinfo

06/16/2016 🔍
09/27/2016 +103 days 🔍
09/27/2016 +0 days 🔍
09/29/2016 +2 days 🔍
01/23/2017 +116 days 🔍
01/27/2017 +4 days 🔍
09/21/2022 +2063 days 🔍

Sourcesinfo

Vendor: microsoft.com

Advisory: seclists.org
Status: Not defined

CVE: CVE-2016-5720 (🔍)
SecurityFocus: 95859 - Skype for Windows CVE-2016-5720 Untrusted Search Path vulnerability

scip Labs: https://www.scip.ch/en/?labs.20140918

Entryinfo

Created: 09/29/2016 03:42 PM
Updated: 09/21/2022 02:45 PM
Changes: 09/29/2016 03:42 PM (60), 04/27/2019 06:02 PM (11), 09/21/2022 02:45 PM (3)
Complete: 🔍

Discussion

No comments yet. Languages: en.

Please log in to comment.

◂ PreviousOverviewNext ▸

Are you interested in using VulDB?

Download the whitepaper to learn more about our service!