Slashdot, SourceForge Back Online After Outage

Several SourceForge, Inc sites, including the popular technology news site Slashdot have been offline for several hours today.

All of Netcraft's globally distributed performance monitors have recorded a solid period of downtime at a number of sites hosted in the VA Software netblock. VA Software is the former name of SourceForge, Inc, which hosts all of the affected sites, including Slashdot, the source code repository, software release site Freshmeat and merchandise supplier ThinkGeek.

Static uptime graph for

Netcraft's live monitoring of can be seen here, reflecting a contiguous outage of approximately 5 hours.

Clinton and Obama XSS Battle Develops

While Clinton and Obama are battling it out in the political arena, security researchers are continuing to find vulnerabilities in the candidates' and supporters' websites. Interestingly, while a typical exploit is to redirect one party's site to their opponent's, the reasons for seeking to discover such vulnerabilities are not always politically motivated.


Following the recent cross-site scripting attacks against Barack Obama's website, Finnish security researcher Harry Sintonen has published an example of a cross-site scripting vulnerability on

Sintonen's example submits a POST request to the Vote Hillary website and injects an iframe, causing the site to display the contents of Barack Obama's website. Unlike the Obama incident, which redirected the user's web browser, Sintonen's method retains the URL in the address bar while displaying the opposing website.

Sintonen told Netcraft that he was inspired by the recent Obama attacks and first examined Hillary Clinton's official website at Sintonen did not find any cross-site scripting vulnerabilities on this site, adding that it looked quite secure, but subsequently found XSS opportunities available on the Vote Hillary website. Sintonen lives in Finland and has no strong interest in US politics.

While the example exploits have so far been relatively benign (limited to redirecting a user to the opponent's website, for example), future cross-site scripting vulnerabilities found on political candidate sites have plenty of scope to be much more serious. Obama's and Clinton's websites both accept monetary contributions towards their campaigns, so cross-site scripting vulnerabilities could be leveraged to steal money and identities from supporters.

Sintonen told Netcraft he informed the webmasters of about this cross-site scripting vulnerability two days ago, but has not yet received a response.

CNN Site Bears the Brunt of Chinese Attackers

The CNN News website has twice been affected since an earlier distributed denial of service attack last Thursday. CNN fixed Thursday's attack by limiting the number of users who could access the site from specific geographical areas.


Subsequently, an attack was purportedly organised to start on Saturday 19th April, but cancelled. However, our performance monitoring graph shows CNN's website suffered downtime within a 3 hour period on Sunday morning, followed by other anomalous activity on Monday morning, where response times were greatly inflated.

Netcraft is continuing to monitor the CNN News website. Live uptime graphs can be viewed here.

Hacker Redirects Barack Obama's site to

A security weakness in Barack Obama's website has been exploited to redirect visitors to Hillary Clinton's website. Visitors who viewed the Community Blogs section of the site were instead presented with Clinton's website as a result of a cross-site scripting vulnerability.

Barack Obama's visitors were redirected to this site.

A user named Mox, from Liverpool, IL, posted an apparent confession in the Community Blogs section on the Barack Obama website yesterday. The subject of the post was, "I am the one who "hacked" Obamas site."

Mox plays down the matter by saying that all he did was exploit some poorly written HTML code before suggesting that it was a cross-site scripting vulnerability that had been exploited. By allowing users to enter characters such as > and " into their blog URLs, JavaScript could be injected into pages in the Community Blogs section and would be executed by subsequent visitors.

A YouTube clip from zennie62 demonstrates the attack. The clip shows a user clicking on the Community Blogs section of the Barack Obama site, which subsequently causes the browser to redirect to The author speculates that "Senator Clinton's staffers possibly hired someone to hack into the Barack Obama website system." No evidence is offered to back up this statement.

Another vulnerability found on the Barack Obama site.

While Mox states that the original issue has now been fixed, a number of similar vulnerabilities have since been identified and remain unfixed, and are documented on, which notes that such vulnerabilities open up opportunities to infect Obama's supporters and site visitors with malware, adware and spyware.

April 2008 Web Server Survey

In the April 2008 survey we received responses from 165,719,150 sites. Most of this month's growth of 3.1 million sites is seen in the US, with Google's Blogger service alone adding 1.1 million extra sites.

lighttpd loses a small number of sites this month, but still maintains a significant foothold in our survey with 1.5 million sites. lighttpd is used to serve some of the content for YouTube, Wikipedia and meebo, and is open sourced under the revised BSD license.

Largely due to the growth at Blogger, Google's developer share increases by 0.54% to 6.08% this month, while Apache falls by 0.27% and Microsoft by 0.14%. In absolute terms, this still means that Apache has gained slightly more sites than Google's 1.07 million, while Microsoft gains 847 thousand sites.

While Blogger continues to run a very large number of sites, Google's new App Engine service is unlikely to make much of an impact on our survey in the immediate future. A limit of 10,000 accounts has been put in place during the preview release stage, and each developer can only create a maximum of three applications.

Total Sites Across All Domains August 1995 - April 2008

Total Sites Across All Domains, August 1995 - April 2008

Graph of market share for top servers across all domains, August 1995 - April 2008

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Google Spreadsheets vulnerability exposes IE users' Gmail, Documents and more

An interesting cross-site scripting (XSS) vulnerability found in the Google Spreadsheets service would have allowed attackers to gain unauthorised access to other Google services, including Gmail and Google Docs.

The vulnerability was discovered by security engineer Billy Rios, and takes advantage of nuances in the way Internet Explorer handles Content-Types for webpages.

Google Spreadsheets XSS

When a spreadsheet is saved and downloaded in CSV format, the Content-Type is set to "text/plain", thereby instructing the client's browser that the document should be treated as plain text. However, if HTML tags are entered into the first cell of the spreadsheet, Internet Explorer detects these tags near the start of the CSV document and instead deduces that it should be treated as HTML. This essentially allowed arbitrary HTML webpages to be served from, which in turn allowed JavaScript to be executed in the context of the site. A remote attacker could exploit this weakness by stealing the user's session cookies and hijacking their session.

Rios points out that Google cookies are valid for all sub domains. This means that when a user logs in to Gmail, the Gmail cookie is also valid for other Google services, such as Google Code, Google Docs, Google Spreadsheets, and more. Cross-site scripting vulnerabilities in any of these sub domains can allow an attacker to hijack a user's session and access other Google services as if they were that user.

Google has fixed the vulnerability discovered by Rios and there have been no reports of the vulnerability being exploited by attackers.