Google fixes Gmail address book flaw

Google has fixed a security hole in several of its services that exposed the address books of Gmail users.

An attacker could create a malicious website that would copy all the entries in a Gmail user's address book, a potential treasure trove for spammers, according to a description of the problem on the "Googling Google" blog. The only condition is that the user would have to be logged in to Gmail or another Google service.

The issue came to light after Google watcher Haochi Chen probed a feature in Google Video over the weekend. The feature, called "Pick People to Email", lets users select contacts from their Gmail address book to send them a video. However, the feature also opened up the address book to others, Chen discovered.

Chen alerted Google over the holiday weekend. Heather Adkins, an information security manager at Google, confirmed the company heard about the Google Video issue and fixed it within hours. The search giant later learned that the same problem also impacted other services and resolved those issues within a day, she said.

Adkins said in an emailed statement: "To our knowledge, no one exploited the vulnerability and no users were impacted."

The problem existed because of the way Google used objects created in a lightweight data interchange format called JavaScript Object Notation, Adkins said. "These objects, if abused, can expose information unintentionally. The fix we employed made sure the objects could not be abused," she added.

Google has regularly had to fix flaws found in its services. Most of these are relatively new types of weaknesses in web applications - for example, cross-site scripting bugs which could help scammers launch phishing attacks. Also, JavaScript-related vulnerabilities could help miscreants launch fully fledged attacks and hostile linking.

Just like traditional software companies, Google appeals to bug hunters to responsibly disclose vulnerabilities and to give it time to fix problems. Adkins said: "Responsible disclosure allows companies like Google to keep users safe by fixing vulnerabilities and resolving security concerns before they are brought to the attention of the bad guys."

Joris Evers writes for CNET News.com