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
NONE
Integrity Impact
HIGH
Availability Impact
NONE
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N
EPSS
Percentile
49.7%
Versions of Ratpack 0.9.1 through and including 1.7.4 are vulnerable to HTTP Response Splitting,
if untrusted and unsanitized data is used to populate the headers of an HTTP response.
An attacker can utilize this vulnerability to have the server issue any HTTP response they specify.
If your application uses arbitrary user input as the value of a response header it is vulnerable.
If your application does not use arbitrary values as response header values, it is not vulnerable.
Previously, Ratpack did not validate response header values.
Now, adding a header value that contains the header value termination characters (CRLF) produces a runtime exception.
Since there is no mechanism for escaping or encoding the termination characters in a String, a runtime exception is necessary.
As potentially dangerous values now cause runtime exceptions, it is a good idea to continue to validate and sanitize any user-supplied values being used as response headers.
We would like to thank Jonathan Leitschuh for reporting this vulnerability.
The following example server uses a query parameter value as a response header, without validating or sanitizing it.
RatpackServer startedServer = RatpackServer.start(server -> {
server.handlers(chain -> chain.all(ctx -> {
// User supplied query parameter
String header = ctx.getRequest().getQueryParams().get("header");
// User supplied data used to populate a header value.
ctx.header("the-header", header)
.render("OK!");
}));
});
Sending a request to the server with the following value for the header
query param would allow the execution of arbitrary Javascript.
Content-Type: text/html
X-XSS-Protection: 0
<script>alert(document.domain)</script>
This vulnerability has been patched in Ratpack version 1.7.5.
The root cause was due to using the netty DefaultHttpHeaders
object with verification disabled.
This vulnerability is now more clearly documented in the Netty documentation: https://github.com/netty/netty/pull/9646
The workaround for this vulnerability is to either not use arbitrary input as response header values or validate such values before being used to ensure they don’t contain a carriage return and/or line feed characters.
If you have any questions or comments about this advisory:
Vendor | Product | Version | CPE |
---|---|---|---|
io.ratpack | ratpack-core | * | cpe:2.3:a:io.ratpack:ratpack-core:*:*:*:*:*:*:*:* |
github.com/advisories/GHSA-mvqp-q37c-wf9j
github.com/ratpack/ratpack/commit/c560a8d10cb8bdd7a526c1ca2e67c8f224ca23ae
github.com/ratpack/ratpack/commit/efb910d38a96494256f36675ef0e5061097dd77d
github.com/ratpack/ratpack/releases/tag/v1.7.5
github.com/ratpack/ratpack/security/advisories/GHSA-mvqp-q37c-wf9j
nvd.nist.gov/vuln/detail/CVE-2019-17513
ratpack.io/versions/1.7.5
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
NONE
Integrity Impact
HIGH
Availability Impact
NONE
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N
EPSS
Percentile
49.7%