CVE-2018-19296

PHPMailer versions prior to 6.0.6 and 5.2.27 are vulnerable to an object injection attack by passing phar:// paths into addAttachment() and other functions that may receive unfiltered local paths, possibly leading to RCE. See this article for more info on this type of vulnerability. Mitigated by blocking the use of paths containing URL-protocol style prefixes such as phar://. Reported by Sehun Oh of cyberone.kr.

Impact

Object injection, possible remote code execution

Patches

Fixed in 6.0.6 and 5.2.27

Workarounds

Validate and sanitise user input before using.

References

https://nvd.nist.gov/vuln/detail/CVE-2018-19296

For more information

If you have any questions or comments about this advisory:

• Open a private issue in the PHPMailer project

PHPMailer before 5.2.27 and 6.x before 6.0.6 is vulnerable to an object injection attack.

Potential object injection vulnerability (CVE-2018-19296).

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)