CVE-2024-25623
highpriority · track · 31EPSS 0.005 · 43 %ileEUUSEPSS · scored 2026-10-27
Mastodon is a free, open-source social network server based on ActivityPub. Prior to versions 4.2.7, 4.1.15, 4.0.15, and 3.5.19, when fetching remote statuses, Mastodon doesn't check that the response from the remote server has a `Content-Type` header value of the Activity Streams media type, which allows a threat actor to upload a crafted Activity Streams document to a remote server and make a Mastodon server fetch it, if the remote server accepts arbitrary user uploads. The vulnerability allows a threat actor to impersonate an account on a remote server that satisfies all of the following properties: allows the attacker to register an account; accepts arbitrary user-uploaded documents and places them on the same domain as the ActivityPub actors; and serves user-uploaded document in response to requests with an `Accept` header value of the Activity Streams media type. Versions 4.2.7, 4.1.15, 4.0.15, and 3.5.19 contain a fix for this issue.
cvss
Technical severity, 0–10. One row per scoring source.
base score 0–10 · higher = more severe · hover a vector to decode
ssvc
A stakeholder decision — act, attend, or track — from exploitation and impact.
weaknesses
The CWE weakness classes this flaw belongs to.
affected products (13)
Products and version ranges known to be affected.
advisories (1)
Vendor and ecosystem advisories describing this.
- BIT-mastodon-2024-25623Lack of media type verification of Activity Streams objects allows impersonation of remote accounts2024-03-31vendor · osvUS
Mastodon is a free, open-source social network server based on ActivityPub. Prior to versions 4.2.7, 4.1.15, 4.0.15, and 3.5.19, when fetching remote statuses, Mastodon doesn't check that the response from the remote server has a `Content-Type` header value of the Activity Streams media type, which allows a threat actor to upload a crafted Activity Streams document to a remote server and make a Mastodon server fetch it, if the remote server accepts arbitrary user uploads. The vulnerability allows a threat actor to impersonate an account on a remote server that satisfies all of the following properties: allows the attacker to register an account; accepts arbitrary user-uploaded documents and places them on the same domain as the ActivityPub actors; and serves user-uploaded document in response to requests with an `Accept` header value of the Activity Streams media type. Versions 4.2.7, 4.1.15, 4.0.15, and 3.5.19 contain a fix for this issue.
also known as (3)
Other names and identifiers for this entity.
sources
Which sources assert this record, and when.
references (7)
External citations — patches, advisories, analysis.
- https://cxsecurity.com/cveshow/CVE-2024-25623/cnnvd
- https://github.com/mastodon/mastodon/commit/9fee5e852669e26f970e278021302e1a203fc022cnnvd
- https://github.com/mastodon/mastodon/security/advisories/GHSA-jhrq-qvrm-qr36cnnvd
- https://github.com/mastodon/mastodon/commit/9fee5e852669e26f970e278021302e1a203fc022enisa_euvd
- https://github.com/mastodon/mastodon/security/advisories/GHSA-jhrq-qvrm-qr36enisa_euvd
- https://github.com/mastodon/mastodon/commit/9fee5e852669e26f970e278021302e1a203fc022Patchnvd
- https://github.com/mastodon/mastodon/security/advisories/GHSA-jhrq-qvrm-qr36Vendor Advisorynvd
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