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MS15-032 - Critical: Cumulative Security Update for Internet Explorer (3038314) - Version: 2.0

Microsoft Security Notifications - Wed, 04/29/2015 - 23:00
Severity Rating: Critical
Revision Note: V2.0 (April 30, 2015): Updated bulletin to inform customers running Internet Explorer on Windows Server 2003 Service Pack 2 that the 3038314 update on the Microsoft Download Center was updated on April 22, 2015. Microsoft recommends that customers who installed the 3038314 update prior to April 22 should reinstall the update to be fully protected from the vulnerabilities discussed in this bulletin.
Summary: This security update resolves vulnerabilities in Internet Explorer. The most severe of the vulnerabilities could allow remote code execution if a user views a specially crafted webpage using Internet Explorer. An attacker who successfully exploited these vulnerabilities could gain the same user rights as the current user. Customers whose accounts are configured to have fewer user rights on the system could be less impacted than those who operate with administrative user rights.
Categories: Security Alerts

TA15-120A: Securing End-to-End Communications

US-CERT Security Alerts - Wed, 04/29/2015 - 20:00
Original release date: April 30, 2015
Systems Affected

Networked systems

Overview

Securing end-to-end communications plays an important role in protecting privacy and preventing some forms of man-in-the-middle (MITM) attacks. Recently, researchers described a MITM attack used to inject code, causing unsecured web browsers around the world to become unwitting participants in a distributed denial-of-service attack. That same code can be employed to deliver an exploit for a particular vulnerability or to take other arbitrary actions.

Description

A MITM attack occurs when a third party inserts itself between the communications of a client and a server. MITM attacks as a general class are not new. Classic MITM attacks (e.g., ARP Spoofing) focus on redirecting network communications. By definition, network infrastructure under attacker control is vulnerable to MITM. However, as technology evolves, new methods for performing MITM attacks evolve as well.

Currently, there is no single technology or configuration to prevent all MITM attacks. However, increasing the complexity with multiple layers of defense may raise the cost for the attacker. Increasing the attacker’s cost in time, effort, or money can be an effective deterrent to avoiding future network compromise.

Generally, encryption and digital certificates provide an effective safeguard against MITM attacks, assuring both the confidentiality and integrity of communications. As a result, modern MITM attacks have focused on taking advantage of weaknesses in the cryptographic infrastructure (e.g., certificate authorities (CAs), web browser certificate stores) or the encryption algorithms and protocols themselves.

Impact

MITM attacks are critical because of the wide range of potential impacts—these include the exposure of sensitive information, modification of trusted data, and injection of data.

Solution

Employing multiple network and browser protection methods forces an attacker to develop different tactics, techniques, and procedures to circumvent the new security configuration.

US-CERT recommends reviewing the following mitigations to reduce vulnerability to MITM attacks:

Update Transport Layer Security and Secure Socket Layer (TLS/SSL)

US-CERT recommends upgrading TLS to 1.1 or higher and ensuring TLS 1.0 and SSL 1, 2, 3.x are disabled, unless required. TLS 1.0 clients can fall back to version 3.0 of the SSL protocol, which is vulnerable to a padding oracle attack when Cypher-Block Chaining mode is used. This method is commonly referred to as the "POODLE" (Padding Oracle on Downgraded Legacy Encryption) attack. Vulnerable TLS implementations can be updated by applying the patch provided by the vendor. Vendor information is available in the National Vulnerability Database (NVD) entry for CVE-2014-3566 [1] or in CERT Vulnerability Note VU#577193 [2]. See US-CERT TA14-290A [3] for additional information on this vulnerability.

Utilize Certificate Pinning

Certificate pinning [4] is a method of associating X.509 certificate and its public key to a specific CA or root. Typically, certificates are validated by checking a verifiable chain of trust back to a trusted root certificate. Certificate pinning bypasses this validation process and allows the user to trust “this certificate only” or “trust only certificates signed by this certificate.” Please use the following resources to configure your browser for certificate pinning:

Microsoft Certificate Trust

The Microsoft Enhanced Mitigation Experience Toolkit (EMET) 5.2 employs a feature named "Certificate Trust" for SSL/TLS certificate pinning. This feature is intended to detect and stop MITM attacks that leverage Public Key Infrastructure. [5]

To use the Certificate Trust, you must provide a list of websites you want to protect and certificate pinning rules applicable to those websites. In order to do this, work with the Certificate Trust Configuration feature of the graphical application or use the Configuration Wizard to automatically configure EMET with the recommended settings. [6] Also, ensure period defaults are updated through patching.

Browser Certificate Pinning

Google Chrome and Mozilla Firefox, among others, perform certificate pinning. They conduct a variation of certificate pinning using the HTTP Strict Transport Security (HSTS), which pre-loads a specific set of public key hashes into the HSTS configuration, limiting valid certificates to only those with the specified indicated public key. Chrome uses HTTPS pins for most Google properties. It uses whitelisted public keys which include keys from Verisign, Google Internet Authority, Equifax, and GeoTrust. Thus, Chrome will not accept certificates for Google properties from other CAs.

Firefox 32 on desktop and later (Firefox 34 and later on Android) has the ability to use certificate pinning. It also has the ability to enforce built-in pinsets (mapping of public keys) information to domains. Firefox will pin all sites that Chrome already does, pin their own sites after audit and cleansing, and pin other popular sites that are already in good standing. Please visit this site on How to Use Pinning [7] and for more information.

Implement DNS-based Authentication of Named Entities (DANE)

DANE is a protocol that allows certificates (X.509) commonly used for TLS. DANE is bound to DNS which uses Domain Name System Security Extensions (DNSSEC). A working group in the Internet Engineering Task Force of DANE developed a new type of DNS record that allows a domain itself to sign statements about which entities are authorized to represent it. [8]

Google Chrome does not use DANE but uses an add-on [9] for support. Mozilla Firefox also uses an add-on [10] to check the existence and validity of DNSSEC.

Use Network Notary Servers

Network notary servers aim to improve the security of communications between computers and websites by enabling browsers to verify website authenticity without relying on CAs. CAs are often considered a security risk because they can be compromised. [11] As a result, browsers can deem fraudulent sites trustworthy and are left vulnerable to MITM attacks.

Each network notary server, or group of servers, is public and can be operated by public/private organizations or individuals. These servers regularly monitor websites and build a history of each site’s certificate data over time. When a browser equipped with a network notary add-on communicates with a website and obtains its certificate information, a user-designated network notary server supplies the browser with historical certificate data for that site. If certificate information provided by the website is inconsistent with the notary’s historical data, a MITM attack could be at play. [12]

References Revision History
  • April 30, 2015: Initial Release

This product is provided subject to this Notification and this Privacy & Use policy.


Categories: Security Alerts

MS15-035 - Critical: Vulnerability in Microsoft Graphics Component Could Allow Remote Code Execution (3046306) - Version: 1.1

Microsoft Security Notifications - Tue, 04/28/2015 - 23:00
Severity Rating: Critical
Revision Note: V1.1 (April 29, 2015): Bulletin revised to correct update replacement entries for all affected software. This is an informational change only.
Summary: This security update resolves a vulnerability in Microsoft Windows. The vulnerability could allow remote code execution if an attacker successfully convinces a user to browse to a specially crafted website, open a specially crafted file, or browse to a working directory that contains a specially crafted Enhanced Metafile (EMF) image file. In all cases, however, an attacker would have no way to force users to take such actions; an attacker would have to convince users to do so, typically by way of enticements in email or Instant Messenger messages.
Categories: Security Alerts

TA15-119A: Top 30 Targeted High Risk Vulnerabilities

US-CERT Security Alerts - Tue, 04/28/2015 - 20:00
Original release date: April 29, 2015
Systems Affected

Systems running unpatched software from Adobe, Microsoft, Oracle, or OpenSSL. 

Overview

Cyber threat actors continue to exploit unpatched software to conduct attacks against critical infrastructure organizations. As many as 85 percent of targeted attacks are preventable [1].

This Alert provides information on the 30 most commonly exploited vulnerabilities used in these attacks, along with prevention and mitigation recommendations.

It is based on analysis completed by the Canadian Cyber Incident Response Centre (CCIRC) and was developed in collaboration with our partners from Canada, New Zealand, the United Kingdom, and the Australian Cyber Security Centre.

Description

Unpatched vulnerabilities allow malicious actors entry points into a network. A set of vulnerabilities are consistently targeted in observed attacks.

Impact

A successful network intrusion can have severe impacts, particularly if the compromise becomes public and sensitive information is exposed. Possible impacts include:

  • Temporary or permanent loss of sensitive or proprietary information,
  • Disruption to regular operations,
  • Financial losses relating to restoring systems and files, and
  • Potential harm to an organization’s reputation.
Solution Maintain up-to-date software

The attack vectors frequently used by malicious actors such as email attachments, compromised “watering hole” websites, and other tools often rely on taking advantage of unpatched vulnerabilities found in widely used software applications. Patching is the process of repairing vulnerabilities found in these software components.

It is necessary for all organizations to establish a strong ongoing patch management process to ensure the proper preventive measures are taken against potential threats. The longer a system remains unpatched, the longer it is vulnerable to being compromised. Once a patch has been publicly released, the underlying vulnerability can be reverse engineered by malicious actors in order to create an exploit. This process has been documented to take anywhere from 24-hours to four days. Timely patching is one of the lowest cost yet most effective steps an organization can take to minimize its exposure to the threats facing its network.

Patch commonly exploited vulnerabilities

Executives should ensure their organization’s information security professionals have patched the following software vulnerabilities. Please see patching information for version specifics.

Microsoft

CVE

Affected Products

Patching Information

CVE-2006-3227​Internet Explorer​Microsoft Malware Protection Encyclopedia Entry

CVE-2008-2244

Office Word

Microsoft Security Bulletin MS08-042

CVE-2009-3129

Office
Office for Mac
Open XML File Format Converter for Mac
Office Excel Viewer
Excel
Office Compatibility Pack for Word, Excel, and PowerPoint

Microsoft Security Bulletin MS09-067

​CVE-2009-3674​Internet Explorer​Microsoft Security Bulletin MS09-072CVE-2010-0806​​Internet Explorer​Microsoft Security Bulletin MS10-018

CVE-2010-3333

Office
Office for Mac
Open XML File Format Converter for Mac

Microsoft Security Bulletin MS10-087

CVE-2011-0101

Excel

 

Microsoft Security Bulletin MS11-021

CVE-2012-0158

Office
SQL Server
BizTalk Server
Commerce Server
Visual FoxPro
Visual Basic

Microsoft Security Bulletin MS12-027

CVE-2012-1856

Office
SQL Server
Commerce Server
Host Integration Server
Visual FoxPro Visual Basic

Microsoft Security Bulletin MS12-060

​CVE-2012-4792​Internet Explorer​Microsoft Security Bulletin MS13-008CVE-2013-0074​​Silverlight and Developer Runtime​Microsoft Security Bulletin MS13-022CVE-2013-1347​Internet Explorer​Microsoft Security Bulletin MS13-038CVE-2014-0322​​​Internet Explorer​Microsoft Security Bulletin MS14-012

CVE-2014-1761

Microsoft Word
Office Word Viewer
Office Compatibility Pack
Office for Mac
Word Automation Services on SharePoint Server
Office Web Apps
Office Web Apps Server

Microsoft Security Bulletin MS14-017​CVE-2014-1776​Internet Explorer​Microsoft Security Bulletin MS14-021 CVE-2014-4114​Windows​Microsoft Security Bulletin MS14-060  Oracle

CVE

Affected Products

Patching Information

CVE-2012-1723

Java Development Kit, SDK, and JRE

Oracle Java SE Critical Patch Update Advisory - June 2012

CVE-2013-2465

Java Development Kit and JRE

Oracle Java SE Critical Patch Update Advisory - June 2013

  Adobe

CVE

Affected Products

Patching Information

​CVE-2009-3953ReaderAcrobat ​Adobe Security Bulletin APSB10-02​​CVE-2010-0188​ReaderAcrobat​Adobe Security Bulletin APSB10-07CVE-2010-2883ReaderAcrobat ​​Adobe Security Bulletin APSB10-21CVE-2011-0611​Flash PlayerAIRReaderAcrobatAdobe Security Bulletin APSB11-07Adobe Security Bulletin APSB11-08​​CVE-2011-2462ReaderAcrobat ​​Adobe Security Bulletin APSB11-30​CVE-2013-0625ColdFusion​​Adobe Security Bulletin APSB13-03CVE-2013-0632​ColdFusion​Adobe Security Bulletin APSB13-03​CVE-2013-2729​ReaderAcrobat​Adobe Security Bulletin APSB13-15​CVE-2013-3336​ColdFusion​Adobe Security Bulletin APSB13-13CVE-2013-5326   ​ColdFusion​Adobe Security Bulletin APSB13-27

CVE-2014-0564

Flash Player
AIR
AIR SDK & Compiler

Adobe Security Bulletin APSB14-22

 OpenSSL

CVE

Affected Product

Patching Information

CVE-2014-0160

OpenSSL

CERT Vulnerability Note VU#720951

  Implement the following four mitigation strategies.

As part of a comprehensive security strategy, network administrators should implement the following four mitigation strategies, which can help prevent targeted cyber attacks.

Ranking

Mitigation Strategy

Rationale

1

Use application whitelisting to help prevent malicious software and unapproved programs from running.

Application whitelisting is one of the best security strategies as it allows only specified programs to run, while blocking all others, including malicious software.

2

Patch applications such as Java, PDF viewers, Flash, web browsers and Microsoft Office.

Vulnerable applications and operating systems are the target of most attacks. Ensuring these are patched with the latest updates greatly reduces the number of exploitable entry points available to an attacker.

3

Patch operating system vulnerabilities.

4

Restrict administrative privileges to operating systems and applications based on user duties.

Restricting these privileges may prevent malware from running or limit its capability to spread through the network.

It is recommended that users review US-CERT Security Tip (ST13-003) and CCIRC’s Mitigation Guidelines for Advanced Persistent Threats for additional background information and to assist in the detection of, response to, and recovery from malicious activity linked to advance persistent threats [2, 3].

References Revision History
  • April 29, 2015: Initial release

This product is provided subject to this Notification and this Privacy & Use policy.


Categories: Security Alerts

MS15-034 - Critical: Vulnerability in HTTP.sys Could Allow Remote Code Execution (3042553) - Version: 1.1

Microsoft Security Notifications - Tue, 04/21/2015 - 23:00
Severity Rating: Critical
Revision Note: V1.1 (April 22, 2015): Bulletin revised to correct the update replacement entries for Windows 8 and Windows Server 2012 in the Affected Software table. This is an informational change only. There were no changes to the update files. Customers who have already successfully updated their systems do not need to take any action.
Summary: This security update resolves a vulnerability in Microsoft Windows. The vulnerability could allow remote code execution if an attacker sends a specially crafted HTTP request to an affected Windows system.
Categories: Security Alerts

MS15-033 - Critical: Vulnerabilities in Microsoft Office Could Allow Remote Code Execution (3048019) - Version: 1.1

Microsoft Security Notifications - Mon, 04/20/2015 - 23:00
Severity Rating: Critical
Revision Note: V1.1 (April 21, 2015): Revised bulletin to announce a detection change for the 2553428 update for supported editions of Microsoft Word 2010. There were no changes to the update files. Customers who have already successfully updated their systems do not need to take any action.
Summary: This security update resolves vulnerabilities in Microsoft Office. The most severe of the vulnerabilities could allow remote code execution if a user opens a specially crafted Microsoft Office file. An attacker who successfully exploited the vulnerabilities could run arbitrary code in the context of the current user. Customers whose accounts are configured to have fewer user rights on the system could be less impacted than those who operate with administrative user rights.
Categories: Security Alerts

TA15-105A: Simda Botnet

US-CERT Security Alerts - Wed, 04/15/2015 - 04:51
Original release date: April 15, 2015
Systems Affected

Microsoft Windows

Overview

The Simda botnet – a network of computers infected with self-propagating malware – has compromised more than 770,000 computers worldwide [1].

The United States Department of Homeland Security (DHS), in collaboration with Interpol and the Federal Bureau of Investigation (FBI), has released this Technical Alert to provide further information about the Simda botnet, along with prevention and mitigation recommendations.

Description

Since 2009, cyber criminals have been targeting computers with unpatched software and compromising them with Simda malware [2]. This malware may re-route a user’s Internet traffic to websites under criminal control or can be used to install additional malware. 

The malicious actors control the network of compromised systems (botnet) through backdoors, giving them remote access to carry out additional attacks or to “sell” control of the botnet to other criminals [1]. The backdoors also morph their presence every few hours, allowing low anti-virus detection rates and the means for stealthy operation [3].    

Impact

A system infected with Simda may allow cyber criminals to harvest user credentials, including banking information; install additional malware; or cause other malicious attacks. The breadth of infected systems allows Simda operators flexibility to load custom features tailored to individual targets.

Solution

Users are recommended to take the following actions to remediate Simda infections:

  • Use and maintain anti-virus software - Anti-virus software recognizes and protects your computer against most known viruses. It is important to keep your anti-virus software up-to-date (see Understanding Anti-Virus Software for more information).
  • Change your passwords - Your original passwords may have been compromised during the infection, so you should change them (see Choosing and Protecting Passwords for more information).
  • Keep your operating system and application software up-to-date - Install software patches so that attackers cannot take advantage of known problems or vulnerabilities. Many operating systems offer automatic updates. If this option is available, you should enable it (see Understanding Patches for more information).
  • Use anti-malware tools - Using a legitimate program that identifies and removes malware can help eliminate an infection. Users can consider employing a remediation tool (examples below) that will help with the removal of Simda from your system.

          Kaspersky Lab : http://www.kaspersky.com/security-scan

          Microsoft: http://www.microsoft.com/security/scanner/en-us/default.aspx

          Trend Micro: http://housecall.trendmicro.com/

  • Check to see if your system is infected – The link below offers a simplified check for beginners and a manual check for experts.

          Cyber Defense Institute:  http://www.cyberdefense.jp/simda/

The above are examples only and do not constitute an exhaustive list. The U.S. government does not endorse or support any particular product or vendor.

References Revision History
  • April 15, 2015: Initial Release

This product is provided subject to this Notification and this Privacy & Use policy.


Categories: Security Alerts

MS15-038 - Important: Vulnerabilities in Microsoft Windows Could Allow Elevation of Privilege (3049576) - Version: 1.0

Microsoft Security Notifications - Mon, 04/13/2015 - 23:00
Severity Rating: Important
Revision Note: V1.0 (April 14, 2015): Bulletin published.
Summary: This security update resolves vulnerabilities in Microsoft Windows. The vulnerabilities could allow elevation of privilege if an attacker logs on to the system and runs a specially crafted application.
Categories: Security Alerts

MS15-040 - Important: Vulnerability in Active Directory Federation Services Could Allow Information Disclosure (3045711) - Version: 1.0

Microsoft Security Notifications - Mon, 04/13/2015 - 23:00
Severity Rating: Important
Revision Note: V1.0 (April 14, 2015): Bulletin published.
Summary: This security update resolves a privately reported vulnerability in Active Directory Federation Services (AD FS). The vulnerability could allow information disclosure if a user leaves their browser open after logging off from an application, and an attacker reopens the application in the browser immediately after the user has logged off.
Categories: Security Alerts

MS15-037 - Important: Vulnerability in Windows Task Scheduler Could Allow Elevation of Privilege (3046269) - Version: 1.0

Microsoft Security Notifications - Mon, 04/13/2015 - 23:00
Severity Rating: Important
Revision Note: V1.0 (April 14, 2015): Bulletin published.
Summary: This security update resolves a vulnerability in Microsoft Windows. An attacker who successfully exploited the vulnerability could leverage a known invalid task to cause Task Scheduler to run a specially crafted application in the context of the System account. An attacker could then install programs; view, change, or delete data; or create new accounts with full user rights.
Categories: Security Alerts

MS15-039 - Important: Vulnerability in XML Core Services Could Allow Security Feature Bypass (3046482) - Version: 1.0

Microsoft Security Notifications - Mon, 04/13/2015 - 23:00
Severity Rating: Important
Revision Note: V1.0 (April 14, 2015): Bulletin published.
Summary: This security update resolves a vulnerability in Microsoft Windows. The vulnerability could allow security feature bypass if a user opens a specially crafted file. In all cases, however, an attacker would have no way to force users to open the specially crafted file; an attacker would have to convince users to open the file, typically by way of an enticement in an email or Instant Messenger message.
Categories: Security Alerts

MS15-041 - Important: Vulnerability in .NET Framework Could Allow Information Disclosure (3048010) - Version: 1.0

Microsoft Security Notifications - Mon, 04/13/2015 - 23:00
Severity Rating: Important
Revision Note: V1.0 (April 14, 2015): Bulletin published.
Summary: This security update resolves a vulnerability in Microsoft .NET Framework. The vulnerability could allow information disclosure if an attacker sends a specially crafted web request to an affected server that has custom error messages disabled. An attacker who successfully exploited the vulnerability would be able to view parts of a web configuration file, which could expose sensitive information.
Categories: Security Alerts

MS15-042 - Important: Vulnerability in Windows Hyper-V Could Allow Denial of Service (3047234) - Version: 1.0

Microsoft Security Notifications - Mon, 04/13/2015 - 23:00
Severity Rating: Important
Revision Note: V1.0 (April 14, 2015): Bulletin published.
Summary: This security update resolves a vulnerability in Microsoft Windows. The vulnerability could allow denial of service if an authenticated attacker runs a specially crafted application in a virtual machine (VM) session. Note that the denial of service does not allow an attacker to execute code or elevate user rights on other VMs running on the Hyper-V host; however, it could cause other VMs on the host to not be manageable in Virtual Machine Manager.
Categories: Security Alerts

MS15-036 - Important: Vulnerabilities in Microsoft SharePoint Server Could Allow Elevation of Privilege (3052044) - Version: 1.0

Microsoft Security Notifications - Mon, 04/13/2015 - 23:00
Severity Rating: Important
Revision Note: V1.0 (April 14, 2015): Bulletin published.
Summary: This security update resolves vulnerabilities in Microsoft Office server and productivity software. The vulnerabilities could allow elevation of privilege if an attacker sends a specially crafted request to an affected SharePoint server. An attacker who successfully exploited the vulnerabilities could read content that the attacker is not authorized to read, use the victim's identity to take actions on the SharePoint site on behalf of the victim, such as change permissions and delete content, and inject malicious content in the browser of the victim.
Categories: Security Alerts

MS14-080 - Critical: Cumulative Security Update for Internet Explorer (3008923) - Version: 3.0

Microsoft Security Notifications - Mon, 04/13/2015 - 23:00
Severity Rating: Critical
Revision Note: V3.0 (April 14, 2015): To comprehensively address issues with the 3008923 security update, customers running Internet Explorer 11 on either Windows 7 or Windows Server 2008 R2 should also install the 3038314 security update released on April 14, 2015. For more information, see MS15-032 or use the following Microsoft Download Center links for your specific configuration: Internet Explorer 11 on Windows 7 for 32-bit Systems (3038314) Internet Explorer 11 on Windows 7 for x64-based Systems Service Pack 1 (3038314) Internet Explorer 11 on Windows Server 2008 R2 for x64-based Systems Service Pack 1 (3038314).
Summary: This security update resolves fourteen privately reported vulnerabilities in Internet Explorer. The most severe of these vulnerabilities could allow remote code execution if a user views a specially crafted webpage using Internet Explorer. An attacker who successfully exploited these vulnerabilities could gain the same user rights as the current user. Customers whose accounts are configured to have fewer user rights on the system could be less impacted than those who operate with administrative user rights.
Categories: Security Alerts

TA15-103A: DNS Zone Transfer AXFR Requests May Leak Domain Information

US-CERT Security Alerts - Mon, 04/13/2015 - 11:36
Original release date: April 13, 2015 | Last revised: April 15, 2015
Systems Affected

Misconfigured Domain Name System (DNS) servers that respond to global Asynchronous Transfer Full Range (AXFR) requests.

Overview

A remote unauthenticated user may request a DNS zone transfer from a public-facing DNS server. If improperly configured, the DNS server may respond with information about the requested zone, revealing internal network structure and potentially sensitive information.

Description

AXFR is a protocol for “zone transfers” for replication of DNS data across multiple DNS servers. Unlike normal DNS queries that require the user to know some DNS information ahead of time, AXFR queries reveal resource records including subdomain names [1]. Because a zone transfer is a single query, it could be used by an adversary to efficiently obtain DNS data.  

A well-known problem with DNS is that zone transfer requests can disclose domain information; for example, see CVE-1999-0532 and a 2002 CERT/CC white paper [2][3]. However, the issue has regained attention due to recent Internet scans still showing a large number of misconfigured DNS servers. Open-source, tested scripts are now available to scan for the possible exposure, increasing the likelihood of exploitation [4].

Impact

A remote unauthenticated user may observe internal network structure, learning information useful for other directed attacks.

Solution

Configure your DNS server to respond only to zone transfer (AXFR) requests from known IP addresses. Many open-source resources give instructions on reconfiguring your DNS server. For example, see this AXFR article for information on testing and fixing the configuration of a BIND DNS server. US-CERT does not endorse or support any particular product or vendor.

References Revision History
  • April 13, 2015: Initial Release

This product is provided subject to this Notification and this Privacy & Use policy.


Categories: Security Alerts

TA15-098A: AAEH

US-CERT Security Alerts - Wed, 04/08/2015 - 20:00
Original release date: April 09, 2015
Systems Affected
  • Microsoft Windows 95, 98, Me, 2000, XP, Vista, 7, and 8
  • Microsoft Server 2003, Server 2008, Server 2008 R2, and Server 2012
Overview

AAEH is a family of polymorphic downloaders created with the primary purpose of downloading other malware, including password stealers, rootkits, fake antivirus, and ransomware.

The United States Department of Homeland Security (DHS), in collaboration with Europol, the Federal Bureau of Investigation (FBI) and the Department of Justice (DOJ), released this Technical Alert to provide further information about the AAEH botnet, along with prevention and mitigation recommendations.

Description

AAEH is often propagated across networks, removable drives (USB/CD/DVD), and through ZIP and RAR archive files. Also known as VObfus, VBObfus, Beebone or Changeup, the polymorphic malware has the ability to change its form with every infection. AAEH is a polymorphic downloader with more than 2 million unique samples. Once installed, it morphs every few hours and rapidly spreads across the network.  AAEH has been used to download other malware families, such as Zeus, Cryptolocker, ZeroAccess, and Cutwail.

Impact

A system infected with AAEH may be employed to distribute malicious software, harvest users' credentials for online services, including banking services, and extort money from users by encrypting key files and then demanding payment in order to return the files to a readable state. AAEH is capable of defeating anti-virus products by blocking connections to IP addresses associated with Internet security companies and by preventing anti-virus tools from running on infected machines.  

Solution

Users are recommended to take the following actions to remediate AAEH infections:

References Revision History
  • April 9, 2015: Initial Release

This product is provided subject to this Notification and this Privacy & Use policy.


Categories: Security Alerts

MS15-022 - Critical: Vulnerabilities in Microsoft Office Could Allow Remote Code Execution (3038999) - Version: 1.1

Microsoft Security Notifications - Wed, 03/25/2015 - 23:00
Severity Rating: Critical
Revision Note: V1.1 (March 26, 2015): Bulletin revised to correct the update replacement entry for Microsoft Excel 2007 Service Pack 3 in the Affected Software table. This is an informational change only. There were no changes to the update files. Customers who have already successfully updated their systems do not need to take any action.
Summary: This security update resolves vulnerabilities in Microsoft Office. The most severe of the vulnerabilities could allow remote code execution if a user opens a specially crafted Microsoft Office file. An attacker who successfully exploited the vulnerabilities could run arbitrary code in the context of the current user. Customers whose accounts are configured to have fewer user rights on the system could be less impacted than those who operate with administrative user rights.
Categories: Security Alerts

MS15-031 - Important: Vulnerability in Schannel Could Allow Security Feature Bypass (3046049) - Version: 1.1

Microsoft Security Notifications - Mon, 03/23/2015 - 23:00
Severity Rating: Important
Revision Note: V1.1 (March 24, 2015): Revised bulletin to add an FAQ directing customers to Microsoft Knowledge Base Article 3050509 for instructions on how to disable EXPORT ciphers after installing the update on Windows Server 2003 systems.
Summary: This security update resolves a vulnerability in Microsoft Windows that facilitates exploitation of the publicly disclosed FREAK technique, an industry-wide issue that is not specific to Windows operating systems. The vulnerability could allow a man-in-the-middle (MiTM) attacker to force the downgrading of the key length of an RSA key to EXPORT-grade length in a TLS connection. Any Windows system using Schannel to connect to a remote TLS server with an exploitable cipher suite is affected.
Categories: Security Alerts

MS15-025 - Important: Vulnerabilities in Windows Kernel Could Allow Elevation of Privilege (3038680) - Version: 2.0

Microsoft Security Notifications - Sun, 03/15/2015 - 23:00
Severity Rating: Important
Revision Note: V2.0 (March 16, 2015): To address a packaging issue for customers who are repeatedly reoffered security update 3033395 when installed on systems running supported editions of Windows Server 2003, Microsoft released update 3033395-v2 for all supported editions of Windows Server 2003. Customers who have not already installed the 3033395 update should install update 3033395-v2 to be fully protected from this vulnerability. To avoid the possibility of future detection logic problems, Microsoft recommends that customers running Windows Server 2003 who have already successfully installed the 3033395 update also apply update 3033395-v2 even though they are already protected from this vulnerability. Customers running other Microsoft operating systems are not affected by this rerelease and do not need to take any action. See Microsoft Knowledge Base Article 3033395 for more information.
Summary: This security update resolves vulnerabilities in Microsoft Windows. The most severe of the vulnerabilities could allow elevation of privilege if an attacker logs on to an affected system and runs a specially crafted application. An attacker who successfully exploited the vulnerability could run arbitrary code in the security context of the account of another user who is logged on to the affected system. An attacker could then install programs; view, change, or delete data; or create new accounts potentially with full user rights.
Categories: Security Alerts
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