#VU75710 LDAP injection in Mastodon - CVE-2023-28853

Vulnerability identifier: #VU75710

Vulnerability risk: Medium

CVSSv4.0: 7 [CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:N/VA:N/SC:H/SI:N/SA:N/E:P/U:Green]

CVE-ID: CVE-2023-28853

CWE-ID: CWE-90

Exploitation vector: Network

Exploit availability: No

Vulnerable software:
Mastodon
Server applications / Other server solutions

Vendor: Mastodon

Description

The vulnerability allows a remote attacker to bypass authentication process.

The vulnerability exists due to improper input validation when processing DLAP queries. A remoteuser can send a specially crafted LDAP query to the application, bypass authentication process and gain unauthorized access to sensitive information.

Mitigation
Install updates from vendor's website.

Vulnerable software versions

Mastodon: 2.5.0 - 2.5.2, 2.6.0 - 2.6.5, 2.7.0 - 2.7.4, 2.8.0 - 2.8.4, 2.9.0 - 2.9.4, 3.0.0 - 3.0.2, 3.1.0 - 3.1.5, 3.2.0 - 3.2.2, 3.3.0 - 3.3.3, 3.4.0 - 3.4.10, 3.5.0 - 3.5.7, 4.0.0 - 4.0.3, 4.1.0 - 4.1.1

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External links
https://github.com/mastodon/mastodon/security/advisories/GHSA-38g9-pfm9-gfqv
https://github.com/mastodon/mastodon/pull/24379
https://github.com/mastodon/mastodon/releases/tag/v3.5.8
https://github.com/mastodon/mastodon/blob/94cbd808b5b3e7999c7e77dc724b7e8c9dd2bdec/app/models/concerns/ldap_authenticable.rb#L7-L14
https://github.com/mastodon/mastodon/blob/94cbd808b5b3e7999c7e77dc724b7e8c9dd2bdec/config/initializers/devise.rb#L398-L414
https://github.com/mastodon/mastodon/releases/tag/v4.1.2
https://github.com/mastodon/mastodon/releases/tag/v4.0.4

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Q & A

Can this vulnerability be exploited remotely?

Yes. This vulnerability can be exploited by a remote authenticated user 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.