CVE-2020-8866 File upload in Groupware Webmail Edition

What is CVE-2020-8866?

CVE-2020-8866 is a medium-severity vulnerability in Debian Debian Linux, published on 23 Mar 2020. Any signed-in user can exploit it over the network, with no action from the victim.

Official description

This vulnerability allows remote attackers to create arbitrary files on affected installations of Horde Groupware Webmail Edition 5.2.22. Authentication is required to exploit this vulnerability. The specific flaw exists within add.php. The issue results from the lack of proper validation of user-supplied data, which can allow the upload of arbitrary files. An attacker can leverage this in conjunction with other vulnerabilities to execute code in the context of the www-data user. Was ZDI-CAN-10125.

Weakness: CWE-434

Which versions are affected by CVE-2020-8866?

It affects 3 products.

Products include Debian Debian Linux, Horde Groupware, Horde Horde Form.

How do I fix CVE-2020-8866?

Apply the vendor's patch.

Is CVE-2020-8866 being exploited?

There is no known exploitation of CVE-2020-8866 in the wild and no public exploit code.

Public exploit code: 2 Exploit-DB entries.

Other vulnerabilities in Debian Debian Linux

• CVE-2015-3306 ProFTPD Improper Access Control Exploited Critical 10.0
• CVE-2025-49113 RoundCube Webmail Deserialization of Untrusted Data Exploited Critical 9.9
• CVE-2026-24061 GNU InetUtils Argument Injection Exploited Critical 9.8
• CVE-2025-39682 Linux Kernel Improper Check for Unusual or Exceptional Conditions Exploited Critical 9.8
• CVE-2024-9680 Mozilla Firefox Use-After-Free Exploited Critical 9.8

All Debian Debian Linux vulnerabilities

Sources

• CVE record
• NVD
• OSV
• GitHub advisory
• How this page is made

Also known as DEBIAN-CVE-2020-8866, DLA-2162-1, GHSA-xrh9-pr8p-fpqj, UBUNTU-CVE-2020-8866.