#VU27870 Information disclosure in Doorkeeper - CVE-2020-10187

Vulnerability identifier: #VU27870

Vulnerability risk: Medium

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

CVE-ID: CVE-2020-10187

CWE-ID: CWE-200

Exploitation vector: Network

Exploit availability: No

Vulnerable software:
Doorkeeper
Client/Desktop applications / Other client software

Vendor: doorkeeper gem

Description

The vulnerability allows a remote attacker to gain access to potentially sensitive information.

The vulnerability exists due to excessive data output by the application. A remote attacker can retrieve the client secret only intended for the OAuth application owner.

Mitigation
Install updates from vendor's website.

Vulnerable software versions

Doorkeeper: 5.0.0 - 5.3.1

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External links
https://github.com/doorkeeper-gem/doorkeeper/commit/25d038022c2fcad45af5b73f9d003cf38ff491f6
https://github.com/doorkeeper-gem/doorkeeper/releases
https://github.com/doorkeeper-gem/doorkeeper/security/advisories/GHSA-j7vx-8mqj-cqp9
https://github.com/rubysec/ruby-advisory-db/pull/446

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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.