A vulnerability was found in LogMeIn LastPass up to 4.9.1. It has been rated as problematic. This issue affects some unknown processing of the file onloadwff.js. The manipulation as part of a HTML Document leads to a denial of service vulnerability. Using CWE to declare the problem leads to CWE-404. The product does not release or incorrectly releases a resource before it is made available for re-use. Impacted is availability. The summary by CVE is:

LogMeIn LastPass through 4.9.1 allows remote attackers to cause a denial of service (browser hang) via an HTML document because the resource consumption of onloadwff.js grows with the number of INPUT elements.

The bug was discovered 12/28/2017. The weakness was disclosed 04/18/2018 by Steve Birstok (haykuro) (Website). The advisory is shared at forums.lastpass.com. The identification of this vulnerability is CVE-2018-10193 since 04/17/2018. The attack may be initiated remotely. No form of authentication is needed for a successful exploitation. It demands that the victim is doing some kind of user interaction. Technical details as well as a public exploit are known. MITRE ATT&CK project uses the attack technique T1499 for this issue.

A public exploit has been developed by Steve Birstok (haykuro) in HTML/Javascript and been published immediately after the advisory. The exploit is available at gist.githack.com. It is declared as proof-of-concept. The vulnerability was handled as a non-public zero-day exploit for at least 110 days. During that time the estimated underground price was around $0-$5k.

There is no information about possible countermeasures known. It may be suggested to replace the affected object with an alternative product.

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Vendor

• LogMeIn

Name

• LastPass

Version

• 4.9.0
• 4.9.1

CPE 2.3info

• 🔍
• 🔍

CPE 2.2info

• 🔍
• 🔍

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