CVE-2016-10045

The isMail transport in PHPMailer before 5.2.20 might allow remote attackers to pass extra parameters to the mail command and consequently execute arbitrary code by leveraging improper interaction between the escapeshellarg function and internal escaping performed in the mail function in PHP. NOTE: this vulnerability exists because of an incorrect fix for CVE-2016-10033.

The isMail transport in PHPMailer before 5.2.20 might allow remote attackers to pass extra parameters to the mail command and consequently execute arbitrary code by leveraging improper interaction between the escapeshellarg function and internal escaping performed in the mail function in PHP. NOTE: this vulnerability exists because of an incorrect fix for CVE-2016-10033.

The isMail transport in PHPMailer before 5.2.20 might allow remote attackers to pass extra parameters to the mail command and consequently execute arbitrary code by leveraging improper interaction between the escapeshellarg function and internal escaping performed in the mail function in PHP. NOTE: this vulnerability exists because of an incorrect fix for CVE-2016-10033.

Impact

The isMail transport in PHPMailer before 5.2.20 might allow remote attackers to pass extra parameters to the mail command and consequently execute arbitrary code by leveraging improper interaction between the escapeshellarg function and internal escaping performed in the mail function in PHP. NOTE: this vulnerability exists because of an incorrect fix for CVE-2016-10033.

This issue really emphasises that it's worth avoiding the built-in PHP mail() function entirely.

Patches

Fixed in 5.2.20

Workarounds

Send via SMTP to localhost instead of calling the mail() function.

References

https://nvd.nist.gov/vuln/detail/CVE-2016-10045 See also https://nvd.nist.gov/vuln/detail/CVE-2016-10033

For more information

If you have any questions or comments about this advisory:

• Open a private issue in the PHPMailer project

The isMail transport in PHPMailer before 5.2.20 might allow remote attackers to pass extra parameters to the mail command and consequently execute arbitrary code by leveraging improper interaction between the escapeshellarg function and internal escaping performed in the mail function in PHP. NOTE: this vulnerability exists because of an incorrect fix for CVE-2016-10033.

The isMail transport in PHPMailer before 5.2.20 might allow remote attackers to pass extra parameters to the mail command and consequently execute arbitrary code by leveraging improper interaction between the escapeshellarg function and internal escaping performed in the mail function in PHP. NOTE: this vulnerability exists because of an incorrect fix for CVE-2016-10033.

Impact

The isMail transport in PHPMailer before 5.2.20 might allow remote attackers to pass extra parameters to the mail command and consequently execute arbitrary code by leveraging improper interaction between the escapeshellarg function and internal escaping performed in the mail function in PHP. NOTE: this vulnerability exists because of an incorrect fix for CVE-2016-10033.

This issue really emphasises that it's worth avoiding the built-in PHP mail() function entirely.

Patches

Fixed in 5.2.20

Workarounds

Send via SMTP to localhost instead of calling the mail() function.

References

https://nvd.nist.gov/vuln/detail/CVE-2016-10045 See also https://nvd.nist.gov/vuln/detail/CVE-2016-10033

For more information

If you have any questions or comments about this advisory:

• Open a private issue in the PHPMailer project

The isMail transport in PHPMailer before 5.2.20 might allow remote attackers to pass extra parameters to the mail command and consequently execute arbitrary code by leveraging improper interaction between the escapeshellarg function and internal escaping performed in the mail function in PHP. NOTE: this vulnerability exists because of an incorrect fix for CVE-2016-10033.

Dawid Golunski discovered that PHPMailer was not properly escaping user input data used as arguments to functions executed by the system shell. An attacker could possibly use this issue to execute arbitrary code. This issue only affected Ubuntu 16.04 ESM. (CVE-2016-10033, CVE-2016-10045)

It was discovered that PHPMailer was not properly escaping characters in certain fields of the code_generator.php example code. An attacker could possibly use this issue to conduct cross-site scripting (XSS) attacks. This issue was only fixed in Ubuntu 16.04 ESM and Ubuntu 18.04 ESM. (CVE-2017-11503)

Yongxiang Li discovered that PHPMailer was not properly converting relative paths provided as user input when adding attachments to messages, which could lead to relative image URLs being treated as absolute local file paths and added as attachments. An attacker could possibly use this issue to access unauthorized resources and expose sensitive information. This issue only affected Ubuntu 16.04 ESM. (CVE-2017-5223)

Sehun Oh discovered that PHPMailer was not properly processing untrusted non-local file attachments, which could lead to an object injection. An attacker could possibly use this issue to execute arbitrary code. This issue only affected Ubuntu 16.04 ESM. (CVE-2018-19296)

Elar Lang discovered that PHPMailer was not properly escaping file attachment names, which could lead to a misinterpretation of file types by entities processing the message. An attacker could possibly use this issue to bypass attachment filters. This issue was only fixed in Ubuntu 16.04 ESM and Ubuntu 20.04 ESM. (CVE-2020-13625)

It was discovered that PHPMailer was not properly handling callables in its validateAddress function, which could result in untrusted code being called should the global namespace contain a function called 'php'. An attacker could possibly use this issue to execute arbitrary code. This issue was only fixed in Ubuntu 20.04 ESM and Ubuntu 22.04 ESM. (CVE-2021-3603)