Cisco IOS fixes 10 denial-of-service vulnerabilities

September 27, 2013 10:12 AM ETIDG News Service - Cisco Systems has patched 10 vulnerabilities that could affect the availability of devices using various versions of its IOS software.

IOS is a multitasking operating system that combines networking and telecommunications functions and is used on many of the company's networking devices.

All of the patched vulnerabilities can affect a device's availability if exploited. They affect Cisco IOS implementations of the Network Time Protocol (NTP), the Internet Key Exchange protocol, the Dynamic Host Configuration Protocol (DHCP), the Resource Reservation Protocol (RSVP), the virtual fragmentation reassembly (VFR) feature for IP version 6 (IPv6), the Zone-Based Firewall (ZBFW) component, the T1/E1 driver queue and the Network Address Translation (NAT) function for DNS (Domain Name System) and PPTP (Point-to-Point Tunneling Protocol).

These vulnerabilities can be exploited by remote, unauthenticated attackers by sending specifically crafted packets over the network to IOS devices that have the affected features enabled.

Depending on the targeted vulnerability, attackers can cause the affected devices to hang, reload, lose connection, lose their ability to route connections or trigger other types of denial-of-service (DoS) conditions.

Workarounds for the NTP, ZBFW, T1/E1 driver queue and RSVP flaws are available and are described in the corresponding security advisories released by Cisco this week. To mitigate the other vulnerabilities, users will have to install patched versions of the IOS software, depending on which versions their devices already use.

"The effectiveness of any workaround or fix depends on specific customer situations, such as product mix, network topology, traffic behavior, and organizational mission," Cisco said. "Because of the variety of affected products and releases, customers should consult their service providers or support organizations to ensure that any applied workaround or fix is the most appropriate in the intended network before it is deployed."

The company is not aware of any malicious exploitation or detailed public disclosure of these vulnerabilities. They were discovered during internal security reviews or while troubleshooting customer service reports.

Reprinted with permission from IDG.net. Story copyright 2012 International Data Group. All rights reserved.

View the original article here

Microsoft Patch Tuesday brings critical Explorer, Outlook fixes

Microsoft has shipped fixes for critical vulnerabilities in Internet Explorer and Outlook as part of September's round of vulnerability fixes.

Overall this month, Microsoft issued 13 bulletins -- 4 for them critical -- that cover 47 vulnerabilities found across Internet Explorer, Outlook, SharePoint, Office and the Windows kernel. It is an exceptionally large number of patches for any one month, said Wolfgang Kandek, CTO of IT security firm Qualys.

[ Security expert Roger A. Grimes offers a guided tour of the latest threats and explains what you can do to stop them in "Fight Today's Malware," InfoWorld's Shop Talk video. | Keep up with key security issues with InfoWorld's Security Adviser blog and Security Central newsletter. ]

Of this round of patches, enterprise security professionals should take a look first at MS13-068, which details a vulnerability allowing for remote code execution in Microsoft Outlook, Kandek said.

This remote code execution vulnerability is particularly dangerous because it does not require user interaction to launch.

The flaw lies in how Outlook handles incoming user certificates, which identify the sender of an email. Outlook's certificate parser can recognize only 256 certificates in any one email.

"The programmer [probably] said 'Well, no one would nest more than 256 certificates,' and no one in their right mind would," Kandek said. "But an attacker would. They always go after this sort of thing."

A hacker could nest more than 256 certificates in an email, which would cause a buffer overflow that could place malicious data in the computer's memory. Microsoft failed to add a mechanism that would check to ensure no more than 256 certificates have been submitted to the parser by any single email.

An exploit for this vulnerability would not require the user to click on anything. Code could automatically be triggered simply by displaying the contents of the email message in a preview window.

MS13-069 for Internet Explorer, a collection of 10 patches, should be dealt with as soon as possible as well, Kandek advised. With these vulnerabilities, an attacker could plant malicious code on a Web page that, when visited by an unpatched browser, could take control of the user's machine, said Amol Sarwate, director of Qualys' Vulnerability Labs .

While Microsoft rated bulletins for Microsoft Office Word, MS13-072, and Excel, MS13-073, as important -- rather than critical -- they still could be harmful to the enterprise if not applied, Kandek said.

Both of these bulletins focus on file format vulnerabilities. They require a user to open a file in order to initiate code that would take control of the computer. Kandek pointed out that environments with sensitive data could be subject to spear-fishing attacks that use these vulnerabilities, in which an attacker may devise a way to fool the user into opening a malicious file.

In addition to the Microsoft patches, administrators should also take a look at the critical patches that Adobe also issued Tuesday for Reader and Flash. Users of Google Chrome and Internet Explorer will have the Flash patches applied automatically, Kandek said.

Joab Jackson covers enterprise software and general technology breaking news for The IDG News Service. Follow Joab on Twitter at @Joab_Jackson. Joab's e-mail address is Joab_Jackson@idg.com

View the original article here