Twitter, Cyber-security, Microsoft ASP.NET Attacks Lead Security News

A cross-site scripting vulnerability impacted as many as 500,000 Twitter users and led a busy week of security news.

The bug was exploited by worms that spread throughout the microblogging service and affected users ranging from the wife of former British Prime Minister Gordon Brown to White House Press Secretary Robert Gibbs. The vulnerability—which Twitter had patched previously—was reopened by a site update unrelated to the launch of "new Twitter," Twitter Security Chief Bob Lord reported.

"First, someone created an account that exploited the issue by turning tweets different colors and causing a pop-up box with text to appear when someone hovered over the link in the tweet," Lord explained. "This is why folks are referring to this an 'OnMouseOver' flaw—the exploit occurred when someone moused over a link.

"Other users took this one step further and added code that caused people to retweet the original tweet without their knowledge."

As it turned out, the worms exploiting the security hole were created by hobbyists rather than malicious hackers.

That was not the case, however, for attacks on sites belonging to the Motion Picture Association of America, Recording Industry Association of America and Aiplex Software, a provider of anti-piracy services. The DoS (denial-of-service) attacks hit the MPAA site Sept. 17, with attacks against RIAA and Aiplex following in the ensuing days. The attacks were retaliation by piracy advocates, and brought down the sites for varying periods of time.

U.S. "cyber-systems" are also facing unauthorized probes on a regular basis, and U.S. Cyber Command chief and NSA Director Gen. Keith Alexander suggested walling off critical infrastructure networks from the rest of the Internet during a roundtable with reporters Sept. 22. Alexander testified before the House Armed Services Committee the following day about the Cyber Command's role in defending U.S. networks.

"Right now, the White House is leading a discussion on, What are the authorities needed and how do we do this and … how will that team operate to defend our country?" he told the committee. "What they will look at across that is, What are the authorities, what do we have legally and then, given that, what do we have to come back to Congress [with] and reshape or mold for authorities to operate in cyber-space?"

Away from Capitol Hill, attackers were busy targeting security hole involving Microsoft's ASP.NET, which is used by developers to build Web applications and XML Web services. According to Microsoft, "limited attacks" have been seen in the wild targeting a vulnerability that exists due to ASP.NET's use of encryption padding, which provides information in error responses that can be used by an attacker to read and tamper with encrypted data.

In addition in updating its advisory with information about the attacks, Microsoft added more information Sept. 24 to its workaround section. Microsoft has said it is working on a patch for the situation.