CVE-2020-5237

Relative Path Traversal (CWE-23) in chunked uploads in oneup/uploader-bundle

References

https://owasp.org/www-community/attacks/Path_Traversal

Credits:

This security vulnerability was found by Thibaud Kehler of SySS GmbH.
E-Mail: [email protected]

The vulnerability was identified in the web service for a chunked file
upload. While the names of the POST parameters vary with the used
frontend, their values are always used in the same way to build a path
where the chunks are stored and assembled temporarily. By not validating
these parameters properly, OneupUploaderBundle is susceptible to a path
traversal vulnerability which can be exploited to upload files to
arbitrary folders on the filesystem. The assembly process can further be
misused with some restrictions to delete and copy files to other
locations.

The vulnerability can be exploited by any users that have legitimate
access to the upload functionality and can lead to arbitrary code
execution, denial of service and disclosure of confidential information.

Input manipulates file paths to reach files outside the intended directory, such as configuration or credential files. Typical impact: unauthorized file read or write outside the intended directory.

CVE-2020-5237 has a CVSS score of 8.8 (High). The vector is network-reachable, low privileges required, and no user interaction. A CVSS score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether this affects your application depends on whether the vulnerable code is present and reachable in your environment. A fixed version is available (2.1.5, 1.9.3); upgrading removes the vulnerable code path.

Kodem intelligence

Already deployed Kodem?

Yes, see version 1.9.3 and 2.1.5.

1. What is CVE-2020-5237? CVE-2020-5237 is a high-severity path traversal vulnerability in oneup/uploader-bundle (composer), affecting versions >= 2.0.0, < 2.1.5. It is fixed in 2.1.5, 1.9.3. Input manipulates file paths to reach files outside the intended directory, such as configuration or credential files.
2. How severe is CVE-2020-5237? CVE-2020-5237 has a CVSS score of 8.8 (High). This score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether it represents real risk in your environment depends on whether the vulnerable code is present and reachable.
3. Which versions of oneup/uploader-bundle are affected by CVE-2020-5237? oneup/uploader-bundle (composer) versions >= 2.0.0, < 2.1.5 is affected.
4. Is there a fix for CVE-2020-5237? Yes. CVE-2020-5237 is fixed in 2.1.5, 1.9.3. Upgrade to this version or later.
5. Is CVE-2020-5237 exploitable, and should I be worried? Whether CVE-2020-5237 is exploitable in your environment depends on whether the vulnerable code is present and reachable. A CVSS score is a worst-case rating; it does not account for your specific deployment, configuration, or usage patterns. Kodem, an Intelligent Application Security platform, uses runtime intelligence to show which vulnerabilities actually execute in production, so you can focus on the ones that represent real risk. Get a demo
6. What actually determines whether CVE-2020-5237 is exploitable, and how bad it is? Exploitability and impact are not fixed properties of a CVE. They depend on runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A high CVSS score on a dependency that never runs is not the same as real risk. Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter.
7. How do I fix CVE-2020-5237?
   • Upgrade oneup/uploader-bundle to 2.1.5 or later
   • Upgrade oneup/uploader-bundle to 1.9.3 or later