#VU50606 Incorrect Regular Expression in Ruby on Rails - CVE-2021-22880

Vulnerability identifier: #VU50606

Vulnerability risk: Medium

CVSSv4.0: 6.6 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:U/U:Green]

CVE-ID: CVE-2021-22880

CWE-ID: CWE-185

Exploitation vector: Network

Exploit availability: No

Vulnerable software:
Ruby on Rails
Universal components / Libraries / Scripting languages

Vendor: Rails

Description

The vulnerability allows a remote attacker to perform a denial of service (DoS) attack.

The vulnerability exists due to incorrect regular expression for money processing format in the PostgreSQL adapter. A remote attacker can pass specially crafted input to the application and perform a regular expression denial of service (ReDOS) attack.

Mitigation
Install updates from vendor's website.

Vulnerable software versions

Ruby on Rails: 5.0.0 rc1 - 5.0.7.2, 5.1.0 rc1 - 5.1.7, 5.2.0 - 5.2.4.4, 6.0.0 - 6.0.3.4, 6.1.0 - 6.1.2

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External links
https://github.com/rails/rails/releases/tag/v6.1.2.1
https://github.com/rails/rails/releases/tag/v6.0.3.5
https://github.com/rails/rails/releases/tag/v5.2.4.5

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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.