CVE-2017-7692 Command injection in n/a
Authenticated attackers can execute arbitrary shell commands on the server by injecting parameters into the sendmail command via email attachments and settings.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2017-7692?
CVE-2017-7692 is a high-severity command injection vulnerability in Squirrelmail Squirrelmail, published on 20 Apr 2017. Any signed-in user can exploit it over the network, with no action from the victim.
Official description
SquirrelMail 1.4.22 (and other versions before 20170427_0200-SVN) allows post-authentication remote code execution via a sendmail.cf file that is mishandled in a popen call. It's possible to exploit this vulnerability to execute arbitrary shell commands on the remote server. The problem is in the Deliver_SendMail.class.php with the initStream function that uses escapeshellcmd() to sanitize the sendmail command before executing it. The use of escapeshellcmd() is not correct in this case since it doesn't escape whitespaces, allowing the injection of arbitrary command parameters. The problem is in -f$envelopefrom within the sendmail command line. Hence, if the target server uses sendmail and SquirrelMail is configured to use it as a command-line program, it's possible to trick sendmail into using an attacker-provided configuration file that triggers the execution of an arbitrary command. For exploitation, the attacker must upload a sendmail.cf file as an email attachment, and inject the sendmail.cf filename with the -C option within the "Options > Personal Informations > Email Address" setting.
Weakness: CWE-20
Which versions are affected by CVE-2017-7692?
It affects 1 product.
Products include Squirrelmail Squirrelmail.
How do I fix CVE-2017-7692?
Apply the vendor's patch.
Upgrade, and pass arguments to programs as a list instead of through a shell. More about Command injection.
Is CVE-2017-7692 being exploited?
There is no known exploitation of CVE-2017-7692 in the wild and no public exploit code.
Public exploit code: 1 Exploit-DB entry.
Other vulnerabilities in Squirrelmail Squirrelmail
Sources
Also known as CVE-2017-5181, DLA-941-1, DSA-3852-1, GHSA-w6jv-pvcq-chp4, MGASA-2017-0121, UBUNTU-CVE-2017-7692.