#VU67622 Path traversal in Rack - CVE-2020-8161

Vulnerability identifier: #VU67622

Vulnerability risk: Medium

CVSSv4.0: 2.7 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N/E:U/U:Green]

CVE-ID: CVE-2020-8161

CWE-ID: CWE-22

Exploitation vector: Network

Exploit availability: No

Vulnerable software:
Rack
Web applications / Modules and components for CMS

Vendor: Rack

Description

The vulnerability allows a remote attacker to perform directory traversal attacks.

The vulnerability exists due to input validation error when processing directory traversal sequences in Rack::Directory app. A remote attacker can send a specially crafted request and read arbitrary files on the system.

Mitigation
Install update from vendor's website.

Vulnerable software versions

Rack: 2.1.0 - 2.1.2

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External links
https://groups.google.com/g/rubyonrails-security/c/IOO1vNZTzPA
https://hackerone.com/reports/434404
https://lists.debian.org/debian-lts-announce/2020/07/msg00006.html
https://usn.ubuntu.com/4561-1/

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Q & A

Can this vulnerability be exploited remotely?

Yes. This vulnerability can be exploited by a remote non-authenticated attacker via the Internet.

Is there known malware, which exploits this vulnerability?

No. We are not aware of malware exploiting this vulnerability.