A Google cross-site scripting vulnerability within a web-hosting service has been discovered by security researchers, the third such problem identified in recent weeks.
This information allows the malicious user to access and modify the user's documents and spreadsheets, view email subjects and search history, Lenssen said.
"It starts to show that Google, by integrating more and more services onto its website, all able to share the same account login, is also exposing its users to growing risks," Lenssen said in his blog.
The vulnerability is similar to one discovered by security researchers last week. Using a proof-of-concept script to target the flaw, the white hat was again able to obtain the user's Google cookies.
The web giant has now provided patches for all three flaws.