Headline
CVE-2022-4877: Fix potential xss issue in missing host response · snoyberg/keter@d41f369
A vulnerability has been found in snoyberg keter up to 1.8.1 and classified as problematic. This vulnerability affects unknown code of the file Keter/Proxy.hs. The manipulation of the argument host leads to cross site scripting. The attack can be initiated remotely. Upgrading to version 1.8.2 is able to address this issue. The name of the patch is d41f3697926b231782a3ad8050f5af1ce5cc40b7. It is recommended to upgrade the affected component. The identifier of this vulnerability is VDB-217444.
@@ -13,7 +13,8 @@ module Keter.Proxy
import qualified Network.HTTP.Conduit as HTTP
import qualified Data.CaseInsensitive as CI
import qualified Keter.HostManager as HostMan
import Blaze.ByteString.Builder (copyByteString)
import Blaze.ByteString.Builder (copyByteString, toByteString)
import Blaze.ByteString.Builder.Html.Word(fromHtmlEscapedByteString)
import Control.Applicative ((<$>), (<|>))
import Control.Monad.IO.Class (liftIO)
import qualified Data.ByteString as S
@@ -284,10 +285,13 @@ missingHostResponse missingHost = Wai.responseBuilder
defaultUnknownHostBody :: ByteString -> ByteString
defaultUnknownHostBody host =
“<!DOCTYPE html>\n<html><head><title>Welcome to Keter</title></head><body><h1>Welcome to Keter</h1><p>The hostname you have provided, <code>”
<> host <> “</code>, is not recognized.</p></body></html>”
<> escapeHtml host <> “</code>, is not recognized.</p></body></html>”
unknownHostResponse :: ByteString -> ByteString -> Wai.Response
unknownHostResponse host body = Wai.responseBuilder
status200
[("Content-Type", “text/html; charset=utf-8”), ("X-Forwarded-Host", host)]
(copyByteString body)
escapeHtml :: ByteString -> ByteString
escapeHtml = toByteString . fromHtmlEscapedByteString