CVE-2016-9920 Command injection in n/a

What is CVE-2016-9920?

CVE-2016-9920 is a high-severity command injection vulnerability in Roundcube Webmail, published on 8 Dec 2016. Any signed-in user can exploit it over the network, with no action from the victim.

Official description

steps/mail/sendmail.inc in Roundcube before 1.1.7 and 1.2.x before 1.2.3, when no SMTP server is configured and the sendmail program is enabled, does not properly restrict the use of custom envelope-from addresses on the sendmail command line, which allows remote authenticated users to execute arbitrary code via a modified HTTP request that sends a crafted e-mail message.

Weakness: CWE-284

Which versions are affected by CVE-2016-9920?

It affects 1 product.

Products include Roundcube Webmail.

How do I fix CVE-2016-9920?

Upgrade to a fixed version.

Upgrade, and pass arguments to programs as a list instead of through a shell. More about Command injection.

Is CVE-2016-9920 being exploited?

There is no known exploitation of CVE-2016-9920 in the wild and no public exploit code.

Public exploit code: 1 proofs of concept on GitHub.

Other vulnerabilities in Roundcube Webmail

• CVE-2024-42009 RoundCube Webmail Cross-Site Scripting Exploited Critical 9.3
• CVE-2025-68461 RoundCube Webmail Cross-site Scripting Exploited High 7.2
• CVE-2008-5619 PHPMailer susceptible to arbitrary code execution Critical 10.0
• CVE-2024-37385 Command injection in n/a Critical 9.8
• CVE-2024-42008 Cross-site scripting in n/a Critical 9.3

All Roundcube Webmail vulnerabilities

Sources

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

Also known as CVE-2017-1000204, DEBIAN-CVE-2016-9920, DLA-737-1, GHSA-f59r-7mfp-ww98, MGASA-2016-0430, UBUNTU-CVE-2016-9920.