[BreachExchange] Hackers can steal the contents of Horde webmail inboxes with one click

[Destry Winant]

https://techcrunch.com/2019/10/31/horde-webmail-inbox-one-click/

A security researcher has found several vulnerabilities in the popular
open-source Horde web email software that allow hackers to
near-invisibly steal the contents of a victim’s inbox.

Horde is one of the most popular free and open-source web email
systems available. It’s built and maintained by a core team of
developers, with contributions from the wider open-source community.
It’s used by universities, libraries and many web hosting providers as
the default email client.

Numan Ozdemir disclosed his vulnerabilities to Horde in May. An
attacker can scrape and download a victim’s entire inbox by tricking
them into clicking a malicious link in an email.

Once clicked, the inbox is downloaded to the attacker’s server.

But the researcher did not hear back from the Horde community.
Security researchers typically give organizations three months to fix
flaws before they are publicly disclosed.

NIST, the government department that maintains the national
vulnerability database, said this week that the flaws pose a “high”
security risk to users.

Ozdemir said some — though not all — of the vulnerabilities were
recently fixed in the latest Horde webmail version. But the Horde
community has not publicly acknowledged the vulnerability — or that
users of earlier versions of the webmail are still vulnerable.

“It is really very easy to steal people’s email,” he told TechCrunch.

His bug report filed with Horde remains open at the time of writing.
We emailed Horde several times, but did not hear back until after
publication. Jan Schneider, a core developer on the project, said the
vulnerabilities “have indeed been fixed, won’t be fixed, or didn’t
even exist anymore at the time of the reporting.”