CVSS2
Attack Vector
NETWORK
Attack Complexity
LOW
Authentication
NONE
Confidentiality Impact
NONE
Integrity Impact
PARTIAL
Availability Impact
NONE
AV:N/AC:L/Au:N/C:N/I:P/A:N
CVSS3
Attack Vector
NETWORK
Attack Complexity
LOW
Privileges Required
NONE
User Interaction
NONE
Scope
UNCHANGED
Confidentiality Impact
HIGH
Integrity Impact
HIGH
Availability Impact
NONE
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N
When using Puma behind a proxy that does not properly validate that the
incoming HTTP request matches the RFC7230 standard, Puma and the frontend
proxy may disagree on where a request starts and ends. This would allow
requests to be smuggled via the front-end proxy to Puma.
The following vulnerabilities are addressed by this advisory:
Transfer-Encoding
headers, when unsupported encodingschunked
.Content-Length
headers and chunk sizes, whenContent-Length
headers, when they should be\r\n
.The vulnerability has been fixed in 5.6.4 and 4.3.12.
When deploying a proxy in front of Puma, turning on any and all functionality
to make sure that the request matches the RFC7230 standard.
These proxy servers are known to have “good” behavior re: this standard and
upgrading Puma may not be necessary. Users are encouraged to validate for
themselves.
CVSS2
Attack Vector
NETWORK
Attack Complexity
LOW
Authentication
NONE
Confidentiality Impact
NONE
Integrity Impact
PARTIAL
Availability Impact
NONE
AV:N/AC:L/Au:N/C:N/I:P/A:N
CVSS3
Attack Vector
NETWORK
Attack Complexity
LOW
Privileges Required
NONE
User Interaction
NONE
Scope
UNCHANGED
Confidentiality Impact
HIGH
Integrity Impact
HIGH
Availability Impact
NONE
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N