Vulnerability CVE-2021-41136


Published: 2021-10-12

Description:
Puma is a HTTP 1.1 server for Ruby/Rack applications. Prior to versions 5.5.1 and 4.3.9, using `puma` with a proxy which forwards HTTP header values which contain the LF character could allow HTTP request smugggling. A client could smuggle a request through a proxy, causing the proxy to send a response back to another unknown client. The only proxy which has this behavior, as far as the Puma team is aware of, is Apache Traffic Server. If the proxy uses persistent connections and the client adds another request in via HTTP pipelining, the proxy may mistake it as the first request's body. Puma, however, would see it as two requests, and when processing the second request, send back a response that the proxy does not expect. If the proxy has reused the persistent connection to Puma to send another request for a different client, the second response from the first client will be sent to the second client. This vulnerability was patched in Puma 5.5.1 and 4.3.9. As a workaround, do not use Apache Traffic Server with `puma`.

Type:

CWE-444

(Inconsistent Interpretation of HTTP Requests ('HTTP Request Smuggling'))

CVSS2 => (AV:N/AC:M/Au:S/C:P/I:P/A:N)

CVSS Base Score
Impact Subscore
Exploitability Subscore
4.9/10
4.9/10
6.8/10
Exploit range
Attack complexity
Authentication
Remote
Medium
Single time
Confidentiality impact
Integrity impact
Availability impact
Partial
Partial
None
Affected software
PUMA -> PUMA 

 References:
https://github.com/puma/puma/security/advisories/GHSA-48w2-rm65-62xx
https://github.com/puma/puma/commit/acdc3ae571dfae0e045cf09a295280127db65c7f

Copyright 2024, cxsecurity.com

 

Back to Top