CVE-2020-27304 Path traversal in civetweb

Critical 9.8 Published 21 Oct 2021 Updated 4 Aug 2024

Attackers can exploit directory traversal in CivetWeb's file upload handler to read or modify arbitrary files on non-Windows systems.

Exploited in the wild: Not known
Login needed: Not needed
Attackable: Over the internet
Victim action needed: Not needed
Fix: Available

What is CVE-2020-27304?

CVE-2020-27304 is a critical path traversal vulnerability in Siemens Sinec Infrastructure Network Services, published on 21 Oct 2021. An attacker can exploit it over the internet without logging in, with no action from the victim.

Official description

The CivetWeb web library does not validate uploaded filepaths when running on an OS other than Windows, when using the built-in HTTP form-based file upload mechanism, via the mg_handle_form_request API. Web applications that use the file upload form handler, and use parts of the user-controlled filename in the output path, are susceptible to directory traversal

Weakness: CWE-22, CWE-23

Which versions are affected by CVE-2020-27304?

It affects 2 products.

Linux distribution packages (1)

civetweb openSUSE:Leap 15.2 All versions 1.15-lp152.2.3.1

Products include Civetweb Project Civetweb, Siemens Sinec Infrastructure Network Services.

How do I fix CVE-2020-27304?

Upgrade to a fixed version.

Upgrade, and resolve every user-supplied path against an allowed base folder before opening it. More about Path traversal.

Is CVE-2020-27304 being exploited?

There is no known exploitation of CVE-2020-27304 in the wild and no public exploit code.

All Siemens Sinec Infrastructure Network Services vulnerabilities

Sources

Also known as AZL-39076, DEBIAN-CVE-2020-27304, GHSA-wphm-mh7c-38cf, UBUNTU-CVE-2020-27304, openSUSE-SU-2021:1424-1.