"Unpatched Vulnerability Allows Hackers to Steal Emails of RainLoop Users"

Security researchers at application security firm Sonar have discovered that an unpatched vulnerability affecting the RainLoop webmail client can be exploited to hijack a user’s session and steal their emails.  RainLoop is an open source web-based email client used by many organizations.  Sonar reported identifying thousands of internet-exposed instances using the Shodan search engine.  The researchers discovered that RainLoop 1.16.0, the latest version of the application released roughly one year ago, is affected by a stored cross-site scripting (XSS) vulnerability that can be exploited against default configurations.  The researchers noted that the attacker could exploit the flaw by simply sending a specially crafted email to a RainLoop user.  Once the victim opens the malicious email, a hidden JavaScript payload is executed in the browser without other user interaction being required.  The security hole, tracked as CVE-2022-29360, is caused by what the researchers describe as a “logic bug after the sanitization process.” The researchers warned that an attacker could exploit the vulnerability to gain access to highly sensitive information that may be stored in the victim’s emails, including passwords, documents and password reset links.  The company has released a video showing the exploit in action.  The vulnerability was initially reported to RainLoop developers in late November 2021, and there were two more responsible disclosure attempts in December and January, but the researchers said they received no response.

SecurityWeek reports: "Unpatched Vulnerability Allows Hackers to Steal Emails of RainLoop Users"