Today Microsoft released 11 security bulletins fixing 24 vulnerabilities in Windows, Windows Server, Exchange Server, Microsoft SharePoint Server, Office Web Apps, Lync, ASP.NET SignalR, and Visual Studio Team Foundation Server 2013. Five of the bulletins address at least one vulnerability rated Critical. Another recently-reported zero-day was not fixed.
Microsoft says that four of the bulletins (MS13-096, MS13-098, MS13-104 and MS13-106) contain a vulnerability which is being exploited in the wild. Of particular concern is MS13-098 which could undermine code signing, one of the more important fundamental protections available today.
- MS13-096: Vulnerability in Microsoft Graphics Component Could Allow Remote Code Execution (2908005) — This update fixes a vulnerability that was being exploited in the wild. The bug was in TIFF parsing and and affected an odd assortment of Windows and Office versions.
- MS13-097: Cumulative Security Update for Internet Explorer (2898785) — Seven vulnerabilities, five of them rated critical, are fixed in the latest cumulative update.
- MS13-098: Vulnerability in Windows Could Allow Remote Code Execution (2893294) — The WinVerifyTrust function, which is involved in verification of code signatures, has a critical vulnerability which could allow a malicious actor to inject malicious code into a signed executable. Microsoft says that this vulnerability is being exploited in the wild.
- MS13-099: Vulnerability in Microsoft Scripting Runtime Object Library Could Allow Remote Code Execution (2909158) — A critical vulnerability in Windows Script 5.6, Windows Script 5.7, and Windows Script 5.8 could allow a malicious web site to take control of a user's computer.
- MS13-100: Vulnerabilities in Microsoft SharePoint Server Could Allow Remote Code Execution (2904244) — Multiple SharePoint page content vulnerabilities, collected as CVE-2013-5059, could run arbitrary code in the security context of the W3WP service account. SharePoint Server 2010, 2013, and Office Web Apps 2013 are affected.
- MS13-101: Vulnerabilities in Windows Kernel-Mode Drivers Could Allow Elevation of Privilege (2880430) — Five vulnerabilities could allow elevation of privilege. An attacker must have valid logon credentials and be able to log on locally and would have to run a malicious program to exploit this vulnerability.
- MS13-102: Vulnerability in LRPC Client Could Allow Elevation of Privilege
(2898715) — Malicious code could elevate privilege by spoofing an LRPC server and sending a specially crafted LPC port message to any LRPC client.
- MS13-104: Vulnerability in Microsoft Office Could Allow Information Disclosure (2909976) — By getting a user to open an Office document on a malicious web site, the attacker could ascertain access tokens used to authenticate the current user on a targeted SharePoint or other Microsoft Office server site. Strangely, Microsoft says both that functional exploit code for this vulnerability is unlikely, and that they are aware of limited, targeted attempts to exploit it. [UPDATE: Thanks to @NoamLiran for pointing me to the exploit research for this vulnerability. I asked Microsoft how the index could be 3 and they replied that "The Exploitability Index only attempts to rate vulnerabilities that can be leveraged for code execution. Vulnerabilities that could allow denial of service, tampering, information disclosure or spoofing will receive an Exploitability Index rating of '3.' The notes for that particular CVE will also reflect the nature of the vulnerability." Click here for Microsoft's rules for the Exploitability Index.]
- MS13-105: Vulnerabilities in Microsoft Exchange Server Could Allow Remote Code Execution (2915705) — This describes four vulnerabilities in Exchange Server, 2 of them in a bundled component from Oracle.
- MS13-106: Vulnerability in a Microsoft Office Shared Component Could Allow Security Feature Bypass (2905238) — Loading a shared Office component as an ActiveX control in IE could allow it to bypass ASLR. The vulnerability has been publicly disclosed and Microsoft is aware of attempts to exploit it.