---
title: "CVE-2009-2422\n    | Ubuntu"
description: Ubuntu is an open source software operating system that runs from the
  desktop, to the cloud, to all your internet connected things.
url: https://ubuntu.com/security/CVE-2009-2422?format=md
keywords: index, follow
---

# CVE-2009-2422

Publication date 10 July 2009

Last updated 25 August 2025

---

Ubuntu priority

**Low**

[Why this priority?](https://ubuntu.com/security/cves/about#priority )

## Cvss 3 Severity Score

**9.8 · Critical**

[Score breakdown](https://ubuntu.com/security/CVE-2009-2422?format=md#impact-score)

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## Description

The example code for the digest authentication functionality
(http\_authentication.rb) in Ruby on Rails before 2.3.3 defines an
authenticate\_or\_request\_with\_http\_digest block that returns nil instead of
false when the user does not exist, which allows context-dependent
attackers to bypass authentication for applications that are derived from
this example by sending an invalid username without a password.

## Status

Show unmaintained releases

| Package | Ubuntu Release | Status |
| --- | --- | --- |
| rails | 9.04 jaunty | Not affected |
| 8.10 intrepid | Not affected |
| 8.04 LTS hardy | Not affected |
| 6.06 LTS dapper | Not affected |

---

* [How can I get the fixes?](https://ubuntu.com/security/cves/about#security)
* [What do statuses mean?](https://ubuntu.com/security/cves/about#statuses)

## Severity score breakdown

CVSS version:
CVSS v3.0

**Base score**

9.8 · Critical

* Base metrics

  | Parameter | Value |
  | --- | --- |
  | Attack vector | Network |
  | Attack complexity | Low |
  | Privileges required | None |
  | User interaction | None |
  | Scope | Unchanged |
  | Confidentiality impact | High |
  | Integrity impact | High |
  | Availability impact | High |
* Scores

  | Parameter | Value |
  | --- | --- |
  | Base score | 9.8 · Critical |
  | Exploitability score | - |
  | Impact score | - |

**Vector:** CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

## References

* [MITRE](https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2009-2422)
* [NVD](https://nvd.nist.gov/vuln/detail/CVE-2009-2422)
* [Launchpad](https://launchpad.net/bugs/cve/CVE-2009-2422)
* [Debian](https://security-tracker.debian.org/tracker/CVE-2009-2422)

### Other references

* <https://www.cve.org/CVERecord?id=CVE-2009-2422>