SSRF in Misskey

CVE-2021-39195

Misskey is an open source, decentralized microblogging platform. In affected versions a Server-Side Request Forgery vulnerability exists in "Upload from URL" and remote attachment handling. This could result in the disclosure of non-public information within the internal network. This has been fixed in 12.90.0. However, if you are using a proxy, you will need to take additional measures. As a workaround this exploit may be avoided by appropriately restricting access to private networks from the host where the application is running.

Vulnerability class: SSRF (Server-Side Request Forgery)

EPSS: 0.011 (62.3th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 7.7 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:N/A:N.

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2021-39195?
CVE-2021-39195 is a high-severity vulnerability in Misskey, classified under Server-Side Request Forgery (SSRF). CVSS score: 7.7/10. Published 2021-09-07.
How severe is CVE-2021-39195?
High severity. CVSS v3 base score is 7.7 out of 10.