"Unpatched Vulnerability Exposes Horde Webmail Servers to Attacks"

Security researchers at Sonar have discovered that the Horde webmail software is affected by a serious vulnerability that can be exploited to gain complete access to an organization's emails.  The flaw is tracked as CVE-2022-30287, and it can be exploited by getting a user to open a specially crafted email.  The researchers stated that the Shodan search shows more than 3,000 internet-exposed instances worldwide, and there are likely many more internal instances that can still be exploited if an organization's email server is exposed.  The researchers stated that this vulnerability allows an attacker to compromise an entire organization's email service.  The only condition is that a single member of this organization views a maliciously crafted email.  While exploiting the vulnerability requires authentication, the flaw can also be exploited remotely by an unauthenticated attacker using cross-site request forgery (CSRF).  The researchers noted that an adversary can create an email that includes an external image, which exploits the vulnerability when it is rendered.  Successfully exploiting the flaw allows the attacker to execute arbitrary code on the underlying server.  The researchers noted that Horde should block the image by default, but they showed how an attacker can bypass this restriction.  The attack works against default Horde configurations, and it does not require any knowledge of the targeted instance.  The researchers also found that the exploit also results in the clear text credentials of the user triggering the exploit getting leaked to the attacker.  Horde is no longer being actively maintained.

SecurityWeek reports: "Unpatched Vulnerability Exposes Horde Webmail Servers to Attacks"