Vulnerability identifier: #VU52001

Vulnerability risk: Medium

CVSSv3.1: 6.5 [CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N/E:U/RL:O/RC:C]

CVE-ID: CVE-2021-28966

CWE-ID: CWE-22

Exploitation vector: Network

Exploit availability: No

Vulnerable software:
Ruby
Universal components / Libraries / Scripting languages

Vendor: Ruby

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 tmpdir library. A remote attacker can send a specially crafted HTTP request and read arbitrary files on the system.

Mitigation
Install updates from vendor's website.

Vulnerable software versions

Ruby: 2.7.0 - 3.0.0

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External links
http://www.ruby-lang.org/en/news/2021/04/05/tempfile-path-traversal-on-windows-cve-2021-28966/

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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.