Feeds

Spam blacklist snafu prompts global gnashing of teeth

Legit IPs blocked in SORBS cockup

Using blade systems to cut costs and sharpen efficiencies

Many email users around the world have been unable to send messages because of ongoing technical problems with a popular service designed to prevent spam from reaching its intended destination.

The problems at SORBS — short for the Spam and Open Relay Blocking System — began on Wednesday and continued into much of Thursday, said Michelle Sullivan, who founded the real-time blacklisting service in 2002 and sold it to GFI Software last year. As a result, messages sent from a huge number of legitimate mail servers were labeled as junkmail and returned to sender.

The widespread outage caused migraines for sales and support staff around the world, as this ongoing Twitter feed demonstrates.

The snafu was the result of a transition from one SORBS system to another that corrupted a database containing potentially millions of IP addresses, Sullivan told The Register. SORBS admins have responded by temporarily clearing out the entire table of faulty listings under the theory that it's better to let through spam than to block real email. They are in the process of rebuilding the database and populating it to user servers around the world, a process that could take up to 24 hours.

Sullivan denied reports such as those here and here that the problem caused all inbound email from Google, Yahoo, and Rackspace, to name a few, to be blocked from SORBS subscribers. The portion of the database that was corrupted stored entries for its DUHL, or dynamic user host list, which mainly contains dynamic IP addresses offered by ISPs, Sullivan explained.

The outage was nonetheless large. There were more than 79,000 corrupted entries, each of which could contain millions of individual IP numbers, said Sullivan, who was unable to provide an estimate of the total number of addresses that were incorrectly being filtered.

The DUHL portion of the database contains a huge amount of historical data, mainly in the form of IP addresses that were listed as spam sources in the past but are no longer considered as such. During a data migration, the flags that were used to indicate that a listing was historical were deleted, causing the addresses to be considered current. SORBS is in the process of restoring the flags. The historical entries are used to help programs rate the likelihood that a given IP address is malicious.

To make matters worse, the database problem coincided with a denial-of-service attack that made it hard for people to reach the SORBS website. The DoS assault has been ongoing for several weeks, Sullivan said, but in the last 24 hours, it turned “smart,” meaning it was able to evade the defensive measures admins had put in place to filter out the garbage traffic.

SORBS has been able to repel the latest attacks, although the site still appears to be sluggish at times. The attacks in no way caused the database problems. ®

Boost IT visibility and business value

More from The Register

next story
Secure microkernel that uses maths to be 'bug free' goes open source
Hacker-repelling, drone-protecting code will soon be yours to tweak as you see fit
14 antivirus apps found to have security problems
Vendors just don't care, says researcher, after finding basic boo-boos in security software
How long is too long to wait for a security fix?
Synology finally patches OpenSSL bugs in Trevor's NAS
Israel's Iron Dome missile tech stolen by Chinese hackers
Corporate raiders Comment Crew fingered for attacks
Roll out the welcome mat to hackers and crackers
Security chap pens guide to bug bounty programs that won't fail like Yahoo!'s
HIDDEN packet sniffer spy tech in MILLIONS of iPhones, iPads – expert
Don't panic though – Apple's backdoor is not wide open to all, guru tells us
Researcher sat on critical IE bugs for THREE YEARS
VUPEN waited for Pwn2Own cash while IE's sandbox leaked
Four fake Google haxbots hit YOUR WEBSITE every day
Goog the perfect ruse to slip into SEO orfice
prev story

Whitepapers

Implementing global e-invoicing with guaranteed legal certainty
Explaining the role local tax compliance plays in successful supply chain management and e-business and how leading global brands are addressing this.
Consolidation: The Foundation for IT Business Transformation
In this whitepaper learn how effective consolidation of IT and business resources can enable multiple, meaningful business benefits.
Application security programs and practises
Follow a few strategies and your organization can gain the full benefits of open source and the cloud without compromising the security of your applications.
How modern custom applications can spur business growth
Learn how to create, deploy and manage custom applications without consuming or expanding the need for scarce, expensive IT resources.
Securing Web Applications Made Simple and Scalable
Learn how automated security testing can provide a simple and scalable way to protect your web applications.