In the perpetual battle against spam, Avinti has thrown its hat into the game with its email gateway plugin. Reading through the article presented a very generic description of the tool: Called NEWT, for Neutralize E-mail-Web Threats, the software is designed to block URLs and IP addresses embedded in inbound spam messages that link to known malware sites, according to company officials. How does a tool like this stack up to the likes of SpamAssassin or Spamhaus's DROP list? Does Avinti's database of known malware links scale to today's amount of incoming spam? . The link for this article located at Network World is no longer available. . Explore the advantages of Avinti's NEWT plugin as it targets spam reduction and effectively barricades malicious URLs.. Avinti NEWT, Email Gateway Plugin, Spam Protection, Malware Defense. . LinuxSecurity.com Team
Serious security flaws that potentially affect hundreds of email gateway products have been discovered in the widely deployed MIME (Multi-Purpose Internet Mail Extensions) protocol. . . .. The vulnerabilities in the MIME extension to the ubiquitous Simple Mail Transport Protocol (SMTP) were uncovered by experts from information security firm Corsaire, which warned of 190 discrete attack vectors. Due to the scale and seriousness of this issue - and the requirement for coordination of vendors with compromised products - Corsaire passed its findings to the UK National Infrastructure Co-ordination Centre (NISCC) team, which is expected to release full details to the public at noon today (Monday 13 September 2004). The MIME vulnerabilities were discovered during a recent Corsaire project to assess the suitability of the email systems used by a large insurance company. The scope of the project was to identify any weaknesses in the organisation's controls for limiting the types of data sent via email and identifying malicious content, such as viruses. During this investigation bespoke tools developed by Corsaire were used to test the system's ability to identify standard and non-standard document formats, and also deliberately malformed MIME encapsulation. The MIME flaws came to light when the same tools were applied to a variety of contemporary mail gateway products. The end result was the discovery of 14 fundamental MIME implementation issues, with 190 discrete attack vectors, Corsaire warned. "In specific terms, these were used to identify over 1000 individual vulnerabilities in only ten common MIME gateway products. At the last count Corsaire was aware of around 90 separate vendors producing MIME products that will also likely be affected," Corsaire said in a prepared statement. The link for this article located at Rob Jaques is no longer available. . A critical issue within the MIME protocol impacts various email servers, risking the exposure of systems to more than 1000 security threats.. MIME Flaws,Email Gateway Security, Attack Vectors. . LinuxSecurity.com Team
This document describes how to setup a spam-blocking email gateway based on open source and freely available software. This procedure is designed for a small to medium sized company with a single domain (multiple domains are possible...just not described here). I will describe how to setup a new computer that is meant to run on your network's DMZ in between the Internet and a corporate email server like Lotus Notes or Microsoft Exchange.. . .. This document describes how to setup a spam-blocking email gateway based on open source and freely available software. This procedure is designed for a small to medium sized company with a single domain (multiple domains are possible...just not described here). I will describe how to setup a new computer that is meant to run on your network's DMZ in between the Internet and a corporate email server like Lotus Notes or Microsoft Exchange. This entire procedure has been developed with security as a primary focus. The operating system is OpenBSD (www.openbsd.org), which is a "Secure by Default" system with an amazing track record for security. The email MTA is Postfix (www.postfix.org) which also has a good record for security and is the easier of the 2 main competitors to the troubled sendmail program. Amavisd-new (https://www.ijs.si/software/amavisd/) is the main filter which processes email from postfix and ensures that we don't lose any mail. Amavisd-new is an huge improvement over the original amavis which was a simple virus scanner, and I think it is the best way of implementing SpamAssassin (https://spamassassin.apache.org/404.html SpamAssassin is the main anti-spam component which works by comparing messages to a ruleset and by using a statistical analysis that is custom built based on your email. In addition to the SpamAssassin spam detection software, we will be using 2 online SPAM databases: DCC (https://www.rhyolite.com/dcc/ and Vipul's Razor (razor.sourceforge.net). These databases work by comparing hashes of our email messages with hashes of known spam. As afinal security precaution, we will run all network processes in a restricted-user/chroot environment,so if an attacker were able to compromise one of the modules, the amount of damage they could do would be seriously limited. There are many different ways to customize the handling of SPAM with this solution. At my company we debated the merits of a number of different methods. We considered using the ability of amavisd to add extensions on spam emails (so a spam email to
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