A vulnerability recently addressed in LastPass could be abused by attackers to expose the last site credentials filled by LastPass.
A freemium password manager, LastPass stores encrypted passwords online and provides users with a web interface to access them, as well as with plugins for web browsers and apps for smartphones.
The newly patched vulnerability impacted the extensions for the Chrome and Opera browsers, and could be exploited in a limited set of circumstances only, LastPass says. The attacker could exploit the flaw to create a clickjacking scenario.
The exploitation process would require for the user to fill a password using the LastPass icon, and then visit a compromised or malicious website. The attacker would also have to trick the user into clicking on the page several times.
“This exploit may result in the last site credentials filled by LastPass to be exposed,” LastPass explains.
Google Project Zero security researcher Tavis Ormandy was the one to discover the vulnerability and report it to LastPass. The researcher says the flaw should be considered High severity, although it won’t work for all URLs.
LastPass pushed a patch on September 12, in the form of version 4.33.0 / v4.33.4. All browser extensions are being updated automatically and no user interaction is required.
“We quickly worked to develop a fix and verified the solution was comprehensive with Tavis,” LastPass notes.
LastPass also recommends a series of best practices, such as to avoid clicking on links from unknown sources, to enable multi-factor authentication for LastPass and other services (bank, email, Twitter, Facebook, etc.), to avoid reusing or disclosing the LastPass master password, to use unique passwords for every account, and to use an antivirus program.
Related: Overall Security of Password Managers Debatable, Cracking Firm Says