SOC status:Duty analyst on shift

UK Cyber Defence
VulnerabilityDeferred

CVE-2024-49363

In affected versions FileServerService (media proxy) in github.com/misskey-dev/misskey 2024.10.1 or earlier did not detect proxy loops, which allows remote actors to execute a self-propagating reflected/amplified distributed denial-of-service via a…

HIGH 7.4EPSS 0.31%

Does this matter?

High impact if exploited, but EPSS currently rates exploitation as unlikely (0.31%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.

Description

Misskey is an open source, federated social media platform. In affected versions FileServerService (media proxy) in github.com/misskey-dev/misskey 2024.10.1 or earlier did not detect proxy loops, which allows remote actors to execute a self-propagating reflected/amplified distributed denial-of-service via a maliciously crafted note. FileServerService.prototype.proxyHandler did not check incoming requests are not coming from another proxy server. An attacker can execute an amplified denial-of-service by sending a nested proxy request to the server and end the request with a malicious redirect back to another nested proxy request. Leading to unbounded recursion until the original request is timed out. This issue has been addressed in version 2024.11.0-alpha.3. Users are advised to upgrade. Users unable to upgrade may configure the reverse proxy to block requests to the proxy with an empty User-Agent header or one containing Misskey/. An attacker can not effectively modify the User-Agent header without making another request to the server.

CVSS 3.1
7.4 HIGHCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:N/I:N/A:H
EPSS
0.31% probability · 24th percentile
CISA KEV
Not listed
Weakness
CWE-405, CWE-674
Source
security-advisories@github.com

Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.