Vulnerability identifier: #VU28239

Vulnerability risk: High

CVSSv3.1: 8.8 [CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H/E:P/RL:O/RC:C]

CVE-ID: CVE-2020-8165

CWE-ID: CWE-502

Exploitation vector: Network

Exploit availability: Yes

Vulnerable software:
activesupport
Operating systems & Components / Operating system package or component

Vendor: Ruby

Description

The vulnerability allows a remote attacker to execute arbitrary code on the target system.

The vulnerability exists due to insecure input validation when processing serialized data in the "MemCacheStore" and "RedisCacheStore". A remote attacker can pass specially crafted data to the application using the "raw: true" parameter and execute arbitrary code on the target system.

Successful exploitation of this vulnerability may result in complete compromise of vulnerable system.

Mitigation
Install updates from vendor's website.

Vulnerable software versions

activesupport: 5.0.0 - 6.0.3.rc1

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External links
http://snyk.io/vuln/SNYK-RUBY-ACTIVESUPPORT-569598
http://github.com/rails/rails/commit/9b4aef4be3dc58eb08f694387857b52be8050954
http://groups.google.com/forum/#!topic/rubyonrails-security/bv6fW4S0Y1c

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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. However, proof of concept for this vulnerability is available.