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Security Research & Defense

Security Advisory 2868725: Recommendation to disable RC4

Tuesday, November 12, 2013

In light of recent research into practical attacks on biases in the RC4 stream cipher, Microsoft is recommending that customers enable TLS1.2 in their services and take steps to retire and deprecate RC4 as used in their TLS implementations. Microsoft recommends TLS1.2 with AES-GCM as a more secure alternative which will provide similar performance.

Security Advisory 2880823: Recommendation to discontinue use of SHA-1

Tuesday, November 12, 2013

Microsoft is recommending that customers and CA’s stop using SHA-1 for cryptographic applications, including use in SSL/TLS and code signing. Microsoft Security Advisory 2880823 has been released along with the policy announcement that Microsoft will stop recognizing the validity of SHA-1 based certificates after 2016. Background Secure Hashing Algorithm 1 (SHA-1) is a message digest algorithm published in 1995 as part of NIST’s Secure Hash Standard.

Technical details of the targeted attack using IE vulnerability CVE-2013-3918

Tuesday, November 12, 2013

Over the weekend we became aware of an active attack relying on an unknown remote code execution vulnerability of a legacy ActiveX component used by Internet Explorer. We are releasing this blog to confirm one more time that the code execution vulnerability will be fixed in today’s UpdateTuesday release and to clarify some details about the second vulnerability reported.

Software defense: safe unlinking and reference count hardening

Wednesday, November 06, 2013

Object lifetime management vulnerabilities represent a very common class of memory safety vulnerability. These vulnerabilities come in many shapes and sizes, and are typically quite difficult to mitigate generically. Vulnerabilities of this type result commonly from incorrect accounting with respect to reference counts describing active users of an object, or improper handling of certain object states or error conditions.

CVE-2013-3906: a graphics vulnerability exploited through Word documents

Tuesday, November 05, 2013

Recently we become aware of a vulnerability of a Microsoft graphics component that is actively exploited in targeted attacks using crafted Word documents sent by email. Today we are releasing Security Advisory 2896666 which includes a proactive Fix it workaround for blocking this attack while we are working on the final update.

Software Defense: mitigating heap corruption vulnerabilities

Tuesday, October 29, 2013

Heap corruption vulnerabilities are the most common type of vulnerability that Microsoft addresses through security updates today. These vulnerabilities typically occur as a result of programming mistakes that make it possible to write beyond the bounds of a heap buffer (a spatial issue) or to place a heap allocated object in an unexpected state such as by using the object after it has been freed (a temporal issue).

Assessing risk for the October 2013 security updates

Tuesday, October 08, 2013

Today we released eight security bulletins addressing 25 CVE’s. Four bulletins have a maximum severity rating of Critical while the other four have a maximum severity rating of Important. We hope that the table below helps you prioritize the deployment of the updates appropriately for your environment. Bulletin Most likely attack vector Max Bulletin Severity Max Exploit-ability Likely first 30 days impact Platform mitigations and key notes MS13-080(Internet Explorer) Victim browses to a malicious webpage.

MS13-080 addresses two vulnerabilities under limited, targeted attacks

Tuesday, October 08, 2013

Today we released MS13-080 which addresses nine CVEs in Internet Explorer. This bulletin fixes multiple security issues, including two critical vulnerabilities that haven been actively exploited in limited targeted attacks, which we will discuss in details in this blog entry. CVE-2013-3893: the final patch after Fix it workaround Previously, Microsoft released Security Advisory 2887505 and made available the Fix it workaround 51001 to provide earlier protection to all customers for an actively exploited security issue that was reported to us.

Software Defense: mitigating stack corruption vulnerabilties

Tuesday, October 01, 2013

Introduction One of the oldest forms of memory safety exploitation is that of stack corruption vulnerabilities, with several early high-profile exploits being of this type. It seems fitting therefore to kick off this Software Defense series by looking at the status of software defense today with respect to this age-old problem.

Software Defense Series: Exploit mitigation and vulnerability detection

Friday, September 27, 2013

Software Defense is a broad topic requiring a multipronged approach including: - the processes and tooling associated with secure development (that we try and encapsulate within the Microsoft SDL), - core OS countermeasures that make exploitation of a given vulnerability more difficult for an attacker, - steps to secure the hardware on which the software runs,