#VU78043 Cross-site scripting in Mastodon - CVE-2023-36459

Vulnerability identifier: #VU78043

Vulnerability risk: Low

CVSSv4.0: 1.2 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:N/VI:N/VA:N/SC:L/SI:L/SA:N/E:U/U:Clear]

CVE-ID: CVE-2023-36459

CWE-ID: CWE-79

Exploitation vector: Network

Exploit availability: No

Vulnerable software:
Mastodon
Server applications / Other server solutions

Vendor: Mastodon

Description

The disclosed vulnerability allows a remote attacker to perform cross-site scripting (XSS) attacks.

The vulnerability exists due to insufficient sanitization of user-supplied data within the oEmbed preview cards. A remote attacker can trick the victim to follow a specially crafted link and execute arbitrary HTML and script code in user's browser in context of vulnerable website.

Successful exploitation of this vulnerability may allow a remote attacker to steal potentially sensitive information, change appearance of the web page, perform phishing and drive-by-download attacks.

Mitigation
Install updates from vendor's website.

Vulnerable software versions

Mastodon: 1.3 - 1.3.3, 1.4.1 - 1.4.7, 1.5.0 - 1.5.1, 1.6.0 - 1.6.1, 2.0.0, 2.1.0 - 2.1.3, 2.2.0, 2.3.0 - 2.3.3, 2.4.0 - 2.4.5, 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 - 3.5.8, 4.0.0 - 4.0.4, 4.1.0 - 4.1.2

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External links
https://github.com/mastodon/mastodon/releases/tag/v3.5.9
https://github.com/mastodon/mastodon/security/advisories/GHSA-ccm4-vgcc-73hp
https://github.com/mastodon/mastodon/commit/6d8e0fae3e96f3cf4febe03fa7fcf5b95ff761b2
https://github.com/mastodon/mastodon/releases/tag/v4.0.5
https://github.com/mastodon/mastodon/releases/tag/v4.1.3
https://www.openwall.com/lists/oss-security/2023/07/06/5

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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.