CVE-2019-9858: debian debian_linux Path Traversal

Vulnerability summary

CVE-2019-9858 is a high (CVSS 8.8) Path Traversal vulnerability in debian debian_linux. EPSS estimates a 18.83% chance of exploitation in the next 30 days, higher than 97.2% of scored vulnerabilities. 3 public exploits are recorded.

Timeline

1. 29-05-2019
   PublishedVulnerability first disclosed.
2. 04-08-2024
   Last modifiedVulnerability information updated.

Description

Remote code execution was discovered in Horde Groupware Webmail 5.2.22 and 5.2.17. Horde/Form/Type.php contains a vulnerable class that handles image upload in forms. When the Horde_Form_Type_image method onSubmit() is called on uploads, it invokes the functions getImage() and _getUpload(), which uses unsanitized user input as a path to save the image. The unsanitized POST parameter object[photo][img][file] is saved in the $upload[img][file] PHP variable, allowing an attacker to manipulate the $tmp_file passed to move_uploaded_file() to save the uploaded file. By setting the parameter to (for example) ../usr/share/horde/static/bd.php, one can write a PHP backdoor inside the web root. The static/ destination folder is a good candidate to drop the backdoor because it is always writable in Horde installations. (The unsanitized POST parameter went probably unnoticed because it's never submitted by the forms, which default to securely using a random path.)

• CWE-22Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')The product uses external input to construct a pathname that is intended to identify a file or directory that is located underneath a restricted parent directory, but the product does not properly neutralize special elements within the pathname that can cause the pathname to resolve to a location that is outside of the restricted directory.