CyberRota Analysis
AI-GeneratedThe vulnerability affects the Kirby content management system, specifically its media handler, which improperly validates filenames, allowing remote attackers to exploit encoded slash characters to traverse outside the intended media directory. This could lead to unauthorized access to arbitrary JSON files and potential deletion of critical job files, posing a significant risk to data integrity. Organizations using affected versions of Kirby, particularly those running on Apache or Nginx with specific configurations, should prioritize upgrading to versions 4.9.5 or 5.5.2 to mitigate this high-severity threat.
Public Exploit Signal
A public exploit, PoC, GitHub repository or Metasploit reference was detected for this CVE.
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Original NVD Description
Kirby is an open-source content management system. Prior to 4.9.5 and 5.5.2, depending on the release line, Kirby's media handler in src/Cms/Media.php allowed Kirby\Cms\Media::thumb() to append a path-bearing filename to a validated parent media directory. On nginx, PHP's built-in server, or Apache with AllowEncodedSlashes enabled, a remote attacker could submit encoded slash characters such as %2f in the filename and traverse outside the parent's media directory. Differences between responses for existing and nonexistent thumbnail configurations disclosed whether an arbitrary .json file existed, and a .json file containing a valid filename key could cause the referenced image to be returned and the job file to be deleted. The related file::version path in src/Filesystem/Asset.php also accepted ../ sequences outside the intended index root. This issue is fixed in versions 4.9.5 and 5.5.2.