Vulnerabilities > CVE-2017-0129 - Improper Certificate Validation vulnerability in Microsoft Lync for mac 2011
Attack vector
NETWORK Attack complexity
LOW Privileges required
NONE Confidentiality impact
NONE Integrity impact
HIGH Availability impact
NONE Summary
Microsoft Lync for Mac 2011 fails to properly validate certificates, allowing remote attackers to alter server-client communications, aka "Microsoft Lync for Mac Certificate Validation Vulnerability."
Vulnerable Configurations
| Part | Description | Count |
|---|---|---|
| Application | 1 |
Common Weakness Enumeration (CWE)
Common Attack Pattern Enumeration and Classification (CAPEC)
- Creating a Rogue Certificate Authority Certificate An attacker exploits a weakness in the MD5 hash algorithm (weak collision resistance) to generate a certificate signing request (CSR) that contains collision blocks in the "to be signed" part. The attacker specially crafts two different, but valid X.509 certificates that when hashed with the MD5 algorithm would yield the same value. The attacker then sends the CSR for one of the certificates to the Certification Authority which uses the MD5 hashing algorithm. That request is completely valid and the Certificate Authority issues an X.509 certificate to the attacker which is signed with its private key. An attacker then takes that signed blob and inserts it into another X.509 certificate that the attacker generated. Due to the MD5 collision, both certificates, though different, hash to the same value and so the signed blob works just as well in the second certificate. The net effect is that the attackers' second X.509 certificate, which the Certification Authority has never seen, is now signed and validated by that Certification Authority. To make the attack more interesting, the second certificate could be not just a regular certificate, but rather itself a signing certificate. Thus the attacker is able to start their own Certification Authority that is anchored in its root of trust in the legitimate Certification Authority that has signed the attackers' first X.509 certificate. If the original Certificate Authority was accepted by default by browsers, so will now the Certificate Authority set up by the attacker and of course any certificates that it signs. So the attacker is now able to generate any SSL certificates to impersonate any web server, and the user's browser will not issue any warning to the victim. This can be used to compromise HTTPS communications and other types of systems where PKI and X.509 certificates may be used (e.g., VPN, IPSec) .
Msbulletin
| bulletin_id | MS17-014 |
| bulletin_url | |
| date | 2017-03-14T00:00:00 |
| impact | Remote Code Execution |
| knowledgebase_id | 4013241 |
| knowledgebase_url | |
| severity | Important |
| title | Security Update for Microsoft Office |
Nessus
| NASL family | MacOS X Local Security Checks |
| NASL id | MACOSX_MS17-014_OFFICE.NASL |
| description | The Microsoft Office application installed on the remote macOS or Mac OS X host is missing a security update. It is, therefore, affected by multiple vulnerabilities : - Multiple remote code execution vulnerabilities exist in Microsoft Office software due to improper handling of objects in memory. An unauthenticated, remote attacker can exploit these, by convincing a user to open a specially crafted document file, to execute arbitrary code in the context of the current user. (CVE-2017-0020, CVE-2017-0030, CVE-2017-0031) - An information disclosure vulnerability exists in Microsoft Office due to improper disclosure of memory contents. An unauthenticated, remote attacker can exploit this to disclose sensitive system memory information by convincing a user to open a specially crafted document file. (CVE-2017-0027) - A denial of service vulnerability exists in Microsoft Office that allows an unauthenticated, remote attacker to cause Office to stop responding by convincing a user to open a specially crafted document file. (CVE-2017-0029) - An out-of-bounds read error exists in Microsoft Office due to an uninitialized variable. A local attacker can exploit this to disclose memory contents by opening a specially crafted document file. (CVE-2017-0105) - A flaw exists in Microsoft Lync for Mac due to improper validation of X.509 certificates. A man-in-the-middle attacker can exploit this, by spoofing a TLS/SSL server via a certificate that appears valid, to disclose or manipulate transmitted data. (CVE-2017-0129) |
| last seen | 2020-06-01 |
| modified | 2020-06-02 |
| plugin id | 97739 |
| published | 2017-03-15 |
| reporter | This script is Copyright (C) 2017-2019 and is owned by Tenable, Inc. or an Affiliate thereof. |
| source | https://www.tenable.com/plugins/nessus/97739 |
| title | MS17-014: Security Update for Microsoft Office (4013241) (macOS) |
| code | |