Headline
CVE-2023-46137: Disordered HTTP pipeline response in twisted.web
Twisted is an event-based framework for internet applications. Prior to version 23.10.0rc1, when sending multiple HTTP requests in one TCP packet, twisted.web will process the requests asynchronously without guaranteeing the response order. If one of the endpoints is controlled by an attacker, the attacker can delay the response on purpose to manipulate the response of the second request when a victim launched two requests using HTTP pipeline. Version 23.10.0rc1 contains a patch for this issue.
Summary
When sending multiple HTTP requests in one TCP packet, twisted.web will process the requests asynchronously without guaranteeing the response order.
Details
There’s an example faulty program:
from twisted.internet import reactor, endpoints from twisted.web import server from twisted.web.proxy import ReverseProxyResource from twisted.web.resource import Resource
class Second(Resource): isLeaf = True def render_GET(self, request): return b’SECOND\n’
class First(Resource): isLeaf = True def render_GET(self, request): def send_response(): request.write(b’FIRST DELAYED\n’) request.finish() reactor.callLater(0.5, send_response) return server.NOT_DONE_YET
root = Resource()
root.putChild(b’second’, Second()) root.putChild(b’first’, First())
endpoint = endpoints.TCP4ServerEndpoint(reactor, 8080) endpoint.listen(server.Site(root)) reactor.run()
When two requests for /first and /second are sent in the same order, the second request will be responded to first.
echo -en “GET /first HTTP/1.1\r\nHost: a\r\n\r\nGET /second HTTP/1.1\r\nHost: a\r\n\r\n” | nc localhost 8080
Impact
If one of the endpoints is controlled by an attacker, the attacker can delay the response on purpose to manipulate the response of the second request when a victim launched two requests using HTTP pipeline.
Related news
Debian Linux Security Advisory 5797-1 - Multiple security issues were found in Twisted, an event-based framework for internet applications, which could result in incorrect ordering of HTTP requests or cross-site scripting.
Red Hat Security Advisory 2024-1640-03 - An update is now available for Red Hat Ansible Automation Platform 2.4. Issues addressed include HTTP request smuggling, denial of service, local file inclusion, memory leak, and traversal vulnerabilities.
Red Hat Security Advisory 2024-1518-03 - An update for python-twisted is now available for Red Hat OpenStack Platform 16.2.
Red Hat Security Advisory 2024-1516-03 - An update for python-twisted is now available for Red Hat OpenStack Platform 16.1.
Red Hat Security Advisory 2024-0322-03 - An update is now available for Red Hat Ansible Automation Platform 2.4. Issues addressed include a local file inclusion vulnerability.
Ubuntu Security Notice 6575-1 - It was discovered that Twisted incorrectly escaped host headers in certain 404 responses. A remote attacker could possibly use this issue to perform HTML and script injection attacks. This issue only affected Ubuntu 20.04 LTS and Ubuntu 22.04 LTS. It was discovered that Twisted incorrectly handled response order when processing multiple HTTP requests. A remote attacker could possibly use this issue to delay responses and manipulate the responses of second requests.
### Summary When sending multiple HTTP requests in one TCP packet, twisted.web will process the requests asynchronously without guaranteeing the response order. ### Details There's an example faulty program: ```python from twisted.internet import reactor, endpoints from twisted.web import server from twisted.web.proxy import ReverseProxyResource from twisted.web.resource import Resource class Second(Resource): isLeaf = True def render_GET(self, request): return b'SECOND\n' class First(Resource): isLeaf = True def render_GET(self, request): def send_response(): request.write(b'FIRST DELAYED\n') request.finish() reactor.callLater(0.5, send_response) return server.NOT_DONE_YET root = Resource() root.putChild(b'second', Second()) root.putChild(b'first', First()) endpoint = endpoints.TCP4ServerEndpoint(reactor, 8080) endpoint.listen(server.Site(root)) reactor.run() ``` When two requests for `/first` and `/second` ...